Random access method and device

ABSTRACT

The disclosure relates to a random access method and device. The method includes: determining a first target uplink carrier among a plurality of uplink carriers corresponding to a target base station, the plurality of uplink carriers includes at least one supplementary uplink (SUL) carrier; transmitting a random access preamble to the target base station using the first target uplink carrier. In the technical solution, a terminal device can determine the first target uplink carrier used for transmitting the random access preamble among the plurality of uplink carriers corresponding to the target base station, and transmit the random access preamble to the target base station using the first target uplink carrier to initiate a random access, so that the random access is implemented in cells configured with the SUL carrier, thus the success rate of the random access is increased.

TECHNICAL FIELD

The disclosure relates to the technical field of communications, andparticularly to a random access method and device.

BACKGROUND

Over the past about 30 years, the mobile communications have evolvedfrom a second-generation (2G) mobile communication network to afifth-generation (5G) mobile communication network by leaps and bounds.In research discussions of the 5G project, supplementary uplink (SUL) isintroduced in a cell to support uplink information of multiple terminaldevices, thus enhancing an uplink coverage in the cell.

In related arts, if a cell that user equipment (UE) accesses isconfigured only with one uplink carrier and one downlink carrier, the UEcan transmit a random access preamble through the uplink carrier toinitiate a random access when performing the random access. However, ifthe cell that the UE accesses is configured with an SUL carrier, thecell includes two uplink carriers. i.e., one SUL carrier and one non-SULcarrier. In the latter case, the UE cannot determine on which uplinkcarrier to initiate a random access process when performing a randomaccess.

SUMMARY

A random access method and device are provided in embodiments of thedisclosure. The technical solutions are described as below.

A first aspect according to the embodiments of the disclosure provides arandom access method applied to a terminal device, the method including:

a first target uplink carrier is determined among a plurality of uplinkcarriers corresponding to a target base station, the plurality of uplinkcarriers including at least one SUL carrier; and

a random access preamble is transmitted to the target base station usingthe first target uplink carrier.

The technical solution in the embodiment of the disclosure may havebeneficial effects as follows.

In the above technical solution, a terminal device can determine thefirst target uplink carrier used for transmitting the random accesspreamble among the plurality of uplink carriers corresponding to thetarget base station, and transmit the random access preamble to thetarget base station using the first target uplink carrier to initiate arandom access, so that the random access is implemented in cellsconfigured with the SUL carrier, thus the success rate of the randomaccess is increased.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

a carrier identifier of the first target uplink carrier is received froma base station; and

the first target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station according tothe carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is received from the basestation includes:

a radio resource control (RRC) message is received from the target basestation, the RRC message including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is received from the basestation includes:

allocation information of the random access preamble is received fromthe target base station, the allocation information of the random accesspreamble including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is received from the basestation includes:

handover command information is received from an original base stationwhen the terminal device performs handover between the original basestation and the target base station, the handover command informationincluding the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is received from the basestation includes:

reconfiguration information is received from the target base stationafter the target base station re-establishes a secondary cell group(SCG) or modifies the SCG, the reconfiguration information including thecarrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

an RRC message including a power threshold is received from the targetbase station;

a reference signal received power (RSRP) of a current downlink carrieris detected;

the first target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station according tothe RSRP and the power threshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the operation that the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the RSRP and the power threshold includes:

the non-SUL carrier is determined as the first target uplink carrier inresponse to the RSRP being greater than or equal to the power threshold;and

the SUL carrier is determined as the first target uplink carrier inresponse to the RSRP being less than the power threshold.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

an RRC message including a quality threshold is received from the targetbase station;

a reference signal received quality (RSRQ) of a current downlink carrieris detected; and

the first target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station according tothe RSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the operation that the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the RSRQ and the quality threshold includes:

the non-SUL carrier is determined as the first target uplink carrier inresponse to the RSRQ being greater than or equal to the qualitythreshold; and

the SUL carrier is determined as the first target uplink carrier inresponse to the RSRQ being less than the quality threshold.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

an RRC message including a power threshold and a quality threshold isreceived from the target base station;

an RSRP and an RSRQ of a current downlink carrier are detected; and

the first target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station according tothe RSRP and the power threshold as well as the RSRQ and the qualitythreshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the operation that the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the RSRP and the power threshold as well as theRSRQ and the quality threshold:

the non-SUL carrier is determined as the first target uplink carrier inresponse to the RSRP being greater than or equal to the power threshold,or in response to the RSRQ being greater than or equal to the qualitythreshold; and

the SUL carrier is determined as first target uplink carrier in responseto the RSRP being less than the power threshold and the RSRQ being lessthan the quality threshold.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

a carrier configured with a physical uplink control channel (PUCCH)among the plurality of uplink carriers is determined as the first targetuplink carrier.

In an embodiment of the disclosure, the operation that the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station includes:

the first target uplink carrier is determined according to a randomaccess resource included in each of the plurality of uplink carriers.

In an embodiment of the disclosure, the method further includes:

random access response information is received from the target basestation, the random access response information including a carrieridentifier of a second target uplink carrier;

the second target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station according tothe carrier identifier of the second target uplink carrier;

scheduled transmission information is transmitted to the target basestation using the second target uplink carrier.

In an embodiment of the disclosure, the method further includes:

a third target uplink carrier is determined among the plurality ofuplink carriers corresponding to the target base station if randomaccess response information is not received from the target base stationin a second preset period;

the random access preamble is transmitted to the target base stationusing the third target uplink carrier.

In an embodiment of the disclosure, the operation that the random accesspreamble is transmitted to the target base station using the thirdtarget uplink carrier includes:

a transmitting power, with which the random access preamble istransmitted to the target base station using the first target uplinkcarrier, is obtained; and

the random access preamble is transmitted to the target base station onthe third target uplink carrier with the transmitting power.

A second aspect according to the embodiments of the disclosure providesa random access method applied to a base station, the method including:

indication information is transmitted to a terminal device, herein theindication information is configured to indicate a first target uplinkcarrier to be determined, by the terminal device for transmitting arandom access preamble, among a plurality of uplink carrierscorresponding to the base station, the plurality of uplink carriersincluding at least one SUL carrier.

In the technical solutions provided by the embodiments of thedisclosure, the base station can configure, for the terminal device, thefirst target uplink carrier used for transmitting the random accesspreamble, so that the terminal device can transmit the random accesspreamble to initiate the random access using the first target uplinkcarrier, thus implementing the random access in the cells configuredwith the SUL carrier and increasing the success rate of the randomaccess.

In an embodiment of the disclosure, the method further includes:

the first target uplink carrier configured for the terminal device totransmit the random access preamble is obtained among the plurality ofuplink carriers;

the operation that the indication information is transmitted to theterminal device includes:

a carrier identifier of the first target uplink carrier is transmittedto the terminal device to enable the terminal device to determine thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the base station according to the carrier identifier ofthe first target uplink carrier.

In an embodiment of the disclosure, the operation that the first targetuplink carrier configured for the terminal device to transmit the randomaccess preamble is obtained among the plurality of uplink carriersincludes:

the first target uplink carrier configured for the terminal device totransmit the random access preamble is obtained according to a randomaccess resource included in each of the plurality of uplink carriers.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is transmitted to theterminal device includes:

an RRC message is transmitted to the terminal device, the RRC messageincluding the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is transmitted to theterminal device includes:

allocation information of the random access preamble is transmitted tothe terminal device, the allocation information of the random accesspreamble including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, the operation that the first targetuplink carrier configured for the terminal device to transmit the randomaccess preamble is obtained among the plurality of uplink carriersincludes:

a handover request is received from an original base station, herein thehandover request indicates that the terminal device performs handoverfrom the original base station to the base station; and

the first target uplink carrier configured for the terminal device totransmit the random access preamble is obtained among the plurality ofuplink carriers according to the handover request;

the operation that the carrier identifier of the first target uplinkcarrier is transmitted to the terminal device includes:

handover response information is transmitted to the original basestation, herein the handover response information includes the carrieridentifier of the first target uplink carrier to enable the originalbase station to transmit, to the terminal device, handover commandinformation including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, the operation that the carrieridentifier of the first target uplink carrier is transmitted to theterminal device includes:

reconfiguration information is transmitted to the terminal device afterthe base station re-establishes an SCG or modifies the SCG, herein thereconfiguration information includes the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, the operation that the indicationinformation is transmitted to the terminal device includes:

a power threshold is transmitted to the terminal device to enable theterminal device to determine, according to the power threshold and anRSRP of a current downlink carrier, the first target uplink carrier fortransmitting the random access preamble among the plurality of uplinkcarriers corresponding to the base station.

In an embodiment of the disclosure, the operation that the indicationinformation is transmitted to the terminal device includes:

a quality threshold is transmitted to the terminal device to enable theterminal device to determine, according to the quality threshold and anRSRQ of a current downlink carrier, the first target uplink carrier fortransmitting the random access preamble among the plurality of uplinkcarriers corresponding to the base station.

In an embodiment of the disclosure, the method further includes:

a second target uplink carrier configured for the terminal device totransmit scheduled transmission information is obtained among theplurality of uplink carriers according to the random access preambletransmitted by the terminal device; and

random access response information is transmitted to the terminal deviceand includes the carrier identifier of the second target uplink carrier.

A third aspect according to the embodiments of the disclosure provides arandom access device, the device including:

a first determination module, configured to determine a first targetuplink carrier among a plurality of uplink carriers corresponding to atarget base station, the plurality of uplink carriers including at leastone SUL carrier; and

a first transmitting module, configured to transmit a random accesspreamble to the target base station using the first target uplinkcarrier

In an embodiment of the disclosure, the first determination moduleincludes:

a first receiving sub-module, configured to receive a carrier identifierof the first target uplink carrier from a base station; and

a first determination sub-module, configured to determine the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, the first receiving sub-moduleincludes:

a first receiving unit, configured to receive an RRC message from thetarget base station, the RRC message including the carrier identifier ofthe first target uplink carrier.

In an embodiment of the disclosure, the first receiving sub-moduleincludes: a second receiving unit, configured to receive allocationinformation of the random access preamble from the target base station,the random access preamble including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, the first receiving sub-moduleincludes:

a third receiving unit, configured to receive handover commandinformation from an original base station when the terminal deviceperforms handover between an original base station and the target basestation, the handover command information including the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, the first receiving sub-moduleincludes:

a fourth receiving unit, configured to receive a reconfiguration messagefrom the target base station after the target base stationre-establishes an SCG or modifies the SCG, the reconfiguration messageincluding the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the first determination moduleincludes:

a second receiving sub-module, configured to receive an RRC messageincluding a power threshold from the target base station;

a first detection sub-module, configured to detect an RSRP of a currentdownlink carrier; and

a second determination sub-module, configured to determine the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station, according to the RSRP and thepower threshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the second determination sub-module includes:

a first determination unit configured to determine the non-SUL carrieras the first target uplink carrier in response to the RSRP being greaterthan or equal to the power threshold; and

a second determination unit, configured to determine the SUL carrier asthe first target uplink carrier in response to the RSRP being less thanthe power threshold.

In an embodiment of the disclosure, the first determination moduleincludes:

a third receiving sub-module, configured to receive an RRC messageincluding a quality threshold from the target base station;

a second detection sub-module, configured to detect an RSRQ of a currentdownlink carrier;

a third determination sub-module, configured to determine the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRQ and thequality threshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the third determination sub-module includes:

a third determination unit configured to determine the non-SUL carrieras the first target uplink carrier in response to the RSRQ being greaterthan or equal to the quality threshold; and

a fourth determination unit configured to determine the SUL carrier asthe first target uplink carrier in response to the RSRQ being less thanthe quality threshold.

In an embodiment of the disclosure, the first determination moduleincludes:

a fourth receiving sub-module, configured to receive, from the targetbase station, an RRC message including a power threshold and a qualitythreshold;

a third detection sub-module, configured to detect an RSRP and an RSRQof a current downlink carrier; and

a fourth determination sub-module, configured to determine the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of the uplink carriersincludes one SUL carrier and one non-SUL carrier;

the fourth determination sub-module includes:

a fifth determination unit, configured to determine the non-SUL carrieras the first target uplink carrier when the RSRP is greater than orequal to the power threshold, or the RSRQ is greater than or equal tothe quality threshold; and

a sixth determination unit, configured to determine the SUL carrier asthe first target uplink carrier in response to the RSRP being less thanthe power threshold and the RSRQ being less than the quality threshold.

In an embodiment of the disclosure, the first determination moduleincludes:

a fifth determination sub-module, configured to determine, as the firsttarget uplink carrier, a carrier configured with a PUCCH among theplurality of uplink carriers.

In an embodiment of the disclosure, the first determination moduleincludes:

a sixth determination sub-module configured to determine the firsttarget uplink carrier according to a random access resource included byeach of the plurality of uplink carriers.

In an embodiment of the disclosure, the device further includes:

a receiving module, configured to receive random access responseinformation including a fifth carrier identifier from the target basestation;

a second determination module, configured to determine a second targetuplink carrier among the plurality of uplink carriers corresponding tothe target base station according to the fifth carrier identifier; and

the second transmitting module, configured to transmit scheduledtransmission information to the target base station using the secondtarget uplink carrier.

In an embodiment of the disclosure, the device further includes:

a third determination module, configured to determine a third targetuplink carrier among the plurality of uplink carriers corresponding tothe target base station if the random access response information is notreceived from the target base station in a second preset period; and

a third transmitting module, configured to transmit the random accesspreamble to the target base station using the third target uplinkcarrier.

In an embodiment of the disclosure, the third transmitting moduleincludes:

a first obtaining sub-module, configured to obtain a transmitting powerwith which the random access preamble is transmitted to the target basestation using the first target uplink carrier;

a first transmitting sub-module, configured to transmit the randomaccess preamble to the target base station on the third target uplinkcarrier with the transmitting power.

A fourth aspect of the embodiments of the disclosure provide a randomaccess device, which includes:

a fourth transmitting module, configured to transmit indicationinformation to a terminal device, the indication information beingconfigured to indicate a first target uplink carrier to be determined,by the terminal device for transmitting a random access preamble, amonga plurality of uplink carriers corresponding to the base station, theplurality of uplink carriers including at least one SUL carrier.

In an embodiment of the disclosure, the device further includes:

a first obtaining module, configured to obtain the first target uplinkcarrier, configured for the terminal device to transmit the randomaccess preamble, among the plurality of uplink carriers;

the fourth transmitting module includes:

a first transmitting sub-module, configured to transmit a carrieridentifier of the first target uplink carrier to the terminal device toenable the terminal device to determine the first target uplink carrieramong the plurality of uplink carriers corresponding to the base stationaccording to the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the first obtaining module includes:

a second obtaining sub-module, configured to obtain the first targetuplink carrier configured for the terminal device to transmit the randomaccess preamble according to a random access resource included by eachof the plurality of uplink carriers.

In an embodiment of the disclosure, the first transmitting sub-moduleincludes:

a first transmitting unit, configured to transmit an RRC messageincluding a carrier identifier of the first target uplink carrier to theterminal device.

In an embodiment of the disclosure, the first transmitting sub-moduleincludes:

a second transmitting unit, configured to transmit allocationinformation of the random access preamble to the terminal device, theallocation information of the random access preamble including thecarrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the first obtaining module includes:

a seventh receiving sub-module, configured to receive a handover requestfrom an original base station, the handover request indicating that theterminal device performs a handover from the original base station tothe base station; and

a third obtaining sub-module, configured to obtain the first targetuplink carrier, configured for the terminal device to transmit therandom access preamble, among the plurality of uplink carriers accordingto the handover request;

the first transmitting module includes:

a third transmitting unit, configured to transmit handover responseinformation to the original base station, the handover responseinformation including the carrier identifier of the first target uplinkcarrier to enable the original base station to transmit handover commandinformation including the carrier identifier of the first target uplinkcarrier to the terminal device.

In an embodiment of the disclosure, the first transmitting sub-moduleincludes:

a fourth transmitting unit, configured to transmit reconfigurationinformation to the terminal device after the base station re-establishesan SCG or modifies the SCG; the reconfiguration information includingthe carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the fourth transmitting moduleincludes:

a second transmitting sub-module, configured to transmit a powerthreshold to the terminal device to enable the terminal device todetermine the first target uplink carrier for transmitting the randomaccess preamble, among the plurality of uplink carriers corresponding tothe base station, according to the power threshold and an RSRP of acurrent downlink carrier.

In an embodiment of the disclosure, the fourth transmitting moduleincludes:

a third transmitting sub-module, configured to transmit a qualitythreshold to the terminal device to enable the terminal device todetermine the first target uplink carrier for transmitting the randomaccess preamble, among the plurality of uplink carriers corresponding tothe base station, according to the quality threshold and an RSRQ of acurrent downlink carrier.

In an embodiment of the disclosure, the device further includes:

a second obtaining module, configured to obtain the second target uplinkcarrier, configured for the terminal device to transmit scheduledtransmission information, among the plurality of uplink carriersaccording to the random access preamble transmitted by the terminaldevice; and

a fifth transmitting module, configured to transmit random accessresponse information to the terminal device, the random access responseinformation including the carrier identifier of the second target uplinkcarrier.

A fifth aspect according to the embodiments of the disclosure provides arandom access device, which includes:

a first processor;

a first memory configured to store instructions executable by the firstprocessor,

the first processor is configured to:

determine a first target uplink carrier among a plurality of uplinkcarriers corresponding to a target base station, the plurality of uplinkcarriers including at least one SUL carrier; and

transmit a random access preamble to the target base station using thefirst target uplink.

A sixth aspect according to the embodiments of the disclosure provides arandom access device, which includes:

a second processor;

a second memory configured to store instructions executable by thesecond processor;

the second processor is configured to:

transmit indication information to a terminal device, the indicationinformation being configured to indicate a first target uplink carrierto be determined, by the terminal device for transmitting a randomaccess preamble, among a plurality of uplink carriers corresponding tothe base station, the plurality of uplink carriers including at leastone SUL carrier.

A seventh aspect according to the embodiments of the disclosure providesa computer readable storage medium having stored computer instructionsthat, when executed by a processor, cause the processor to implementoperations of the method according to any embodiment in the firstaspect.

An eighth aspect according to the embodiments of the disclosure providesa computer readable storage medium having stored computer instructionsthat, when executed by a processor, cause the processor to implementoperations of the method according to any embodiment in the secondaspect.

It should be understood that the general description above and thefollowing detailed description in the disclosure are merely exemplaryand explanatory and are not intended to limit the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments consistent with thepresent disclosure and, together with the description, serve to explainthe principles of the present disclosure.

FIG. 1a is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1b is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1c is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1d is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1e is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1f is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1g is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1h is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1i is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 1j is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2a is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2b is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2c is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2d is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2e is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 2f is a flowchart illustrating a random access method according toan exemplary embodiment;

FIG. 3 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment;

FIG. 4 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment;

FIG. 5 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment;

FIG. 6a is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6b is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6c is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6d is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6e is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6f is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6g is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6h is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6i is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6j is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6k is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6l is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6m is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6n is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6o is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6p is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 6q is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7a is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7b is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7c is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7d is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7e is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7f is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7g is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7h is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7i is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 7j is a structural schematic diagram illustrating a random accessdevice according to an exemplary embodiment;

FIG. 8 is a structural block diagram illustrating a random access deviceaccording to an exemplary embodiment; and

FIG. 9 is a structural block diagram illustrating a random access deviceaccording to an exemplary embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. The followingdescription refers to the accompanying drawings in which the samenumbers in different drawings represent the same or similar elementsunless otherwise represented. The implementations set forth in thefollowing description of exemplary embodiments do not represent allimplementations consistent with the present disclosure. Instead, theyare merely examples of apparatuses and methods consistent with aspectsrelated to the present disclosure as recited in the appended claims.

The technical solutions provided by the embodiments of the disclosurerelate to a terminal device and a base station that are connected toeach other via a mobile communication network. The terminal can be acell phone, a tablet, a smart watch and other device with functions ofmobile communication, and there are no limits made in the embodiments ofthe disclosure. In related art, if a cell accessed by a terminal deviceis configured with an SUL carrier, the cell includes two uplinkcarriers, i.e., one SUL carrier and one non-SUL carrier. As a result,the terminal device cannot determine on which uplink carrier to initiatea random access process when the random access is performed. In thetechnical solutions provided by the embodiments of the disclosure, theterminal device can determine a first target uplink carrier used fortransmitting a random access preamble among a plurality of uplinkcarriers corresponding to a target base station, and transmit a randomaccess preamble to the target base station using the first target uplinkcarrier to initiate a random access, so that the random access isimplemented in cells configured with the SUL carrier, thus the successrate of the random access is increased.

In the embodiments of the disclosure, a random access method isprovided, and an execution subject of the method includes a terminaldevice and a base station. Two sets of embodiments are arranged in thedisclosure depending on execution subjects of the methods, which aredescribed as follows.

Terminal Device Side

FIG. 1a is a flowchart illustrating a random access method according toan exemplary embodiment, herein the method is applied to the terminaldevice. As illustrated in FIG. 1a , the method includes followingoperations 101 and 102.

In operation 101, a first target uplink carrier is determined among aplurality of uplink carriers corresponding to a target base station, theplurality of uplink carriers including at least one supplementary uplink(SUL) carrier.

Exemplarily, the plurality of uplink carriers corresponding to thetarget base station can include at least one SUL carrier and one non-SULcarrier, herein the non-SUL carrier is usually a carrier in a highfrequency band and the SUL carrier is usually a carrier in a lowfrequency band. In the embodiments of the disclosure, a target basestation will be described as an example, herein the target base stationincludes: two uplink carriers including one SUL carrier and one non-SULcarrier, and a downlink carrier paired with the two uplink carriers.

The target base station performs system broadcasting according to apreset time interval. herein a system broadcasting message can include acarrier identifier of the SUL carrier, a carrier identifier of a non-SULcarrier and a carrier identifier of a downlink carrier. If an uplinkcarrier paired with the downlink carrier is pre-agreed between theterminal device and the target base station agree, the systembroadcasting message can merely include the carrier identifier of theSUL carrier and the carrier identifier of the downlink carrier. In thiscase, the terminal device can obtain the carrier identifier of anothernon-SUL carrier paired with the downlink carrier according to theagreement after receiving the system broadcasting message. Or, if adownlink carrier paired with the uplink carrier is pre-agreed betweenthe terminal device and the target base station, the system broadcastingmessage can merely include the carrier identifier of the SUL carrier andthe carrier identifier of the non-SUL carrier. In this case, theterminal device can obtain the carrier identifier of the downlinkcarrier paired with the non-SUL carrier according to the agreement afterreceiving the system broadcasting message. The carrier identifier can bean identity (ID) of the carrier pre-agreed between the terminal and thetarget base station; or if the frequencies of the two uplink carriersand the downlink carrier are different from each other, the carrieridentifier can also be the frequency of each carrier. There are nolimits made in the embodiments of the disclosure.

According to an embodiment of the disclosure, the terminal device canmonitor the system broadcasting message of the target base station andaccess the target base station according to the system broadcastingmessage. During an interaction process between the terminal device andthe target base station, the target base station usually configures aphysical uplink control channel (PUCCH) on an uplink carrier with abetter signal quality to ensure a good communication quality of thePUCCH, namely the reliability in transmission of a control signaling,thus the terminal can determine, as a first target uplink carrier, acarrier configured with the PUCCH among the plurality of uplink carrierscorresponding to the target base station and transmit a random accesspreamble using the determined carrier, thereby improving the reliabilityin transmission of the random access preamble. For example, if thetarget base station configures the PUCCH on the SUL carrier, theterminal device can determine the SUL carrier as the first target uplinkcarrier; if the target base station configures the PUCCH on the non-SULcarrier, the terminal can determine the non-SUL carrier as the firsttarget uplink carrier; if the target base station configures that thePUCCH can be dynamically regulated on the SUL carrier and the non-SULcarrier, then based on a time when the random access is initiated, theterminal device can also determine, as the first target uplink carrier,the SUL carrier or the non-SUL carrier which is configured with thePUCCH at the time when the random access is initiated.

According to an embodiment of the disclosure, the terminal device canalso obtain a random access resource included by each of the pluralityof uplink carriers respectively and determine the first target uplinkcarrier according to the random access resource included by each uplinkcarrier. For example, the terminal device can obtain the random accessresources included by the SUL carrier and the non-SUL carrierrespectively, and then obtain, a carrier where the earliest-arrivingrandom access resource is on, as the first target uplink carrieraccording to the time when the random access is initiated, herein theearliest-arriving random access resource is a resource that arrives at atime closest to the time when the random access is initiated.

In operation 102, the random access preamble is transmitted to thetarget base station using the first target uplink carrier.

Exemplarily, after the first target uplink carrier for transmitting therandom access preamble is determined among the plurality of uplinkcarriers, the terminal device can transmit the random access preamble tothe target base station using the first target uplink carrier.Specifically, the terminal device can transmit the random accesspreamble using a preset first transmitting power and wait to receiverandom access response information from the target base station. if therandom access response information is not received from the target basestation in a second preset period, the terminal device can continue totransmit the random access preamble on the first target uplink carrierusing a preset second transmitting power and re-initiate the randomaccess. Or, the terminal device can determine a second target uplinkcarrier, other than the first target uplink carrier, among the pluralityof uplink carriers, and transmit the random access preamble using thesecond target uplink carrier.

In the technical solutions provided by the embodiments of thedisclosure, a terminal device can determine a first target uplinkcarrier used for transmitting a random access preamble among a pluralityof uplink carriers corresponding to a target base station, and transmita random access preamble to the target base station using the firsttarget uplink carrier to initiate a random access, so that the randomaccess is implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG. 1b ,determining a first target uplink carrier among a plurality of uplinkcarriers corresponding to a target base station can be implemented byoperations 1011 and 1012.

In operation 1011, a carrier identifier of the first target uplinkcarrier is received from a base station.

In operation 1012, the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the carrier identifier of the first target uplinkcarrier.

Exemplarily, when determining that the terminal device needs to initiatea random access, the target base station can determine the first targetuplink carrier configured for the terminal device to transmit the randomaccess preamble among the plurality of uplink carriers corresponding tothe target base station and transmit the carrier identifier of the firsttarget uplink carrier to the terminal device. After receiving thecarrier identifier of the first target uplink carrier from the targetbase station, the terminal device can obtain, as the first target uplinkcarrier, an uplink carrier with a carrier identifier same as the carrieridentifier of the first target uplink carrier, among the plurality ofuplink carrier.

The carrier identifier of the first target uplink carrier can be: acarrier name of the first target uplink carrier, i.e., an SUL carrier ora non-SUL carrier; or an ID of the first target uplink carrierpre-agreed between the terminal device and the target base station; or acarrier index number, i.e., the index number of each uplink carrierpre-agreed between the terminal and the base station, when the targetbase station transmit the carrier identifier of the first target uplinkcarrier, it can directly transmit the index number of the first targetuplink carrier. If frequencies of the plurality of uplink carrierscorresponding to the target base station are different from each other,the carrier identifier of the first target uplink carrier can also be acarrier frequency of the first target uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 1c , theoperation 1011 of receiving a carrier identifier of the first targetuplink carrier can be implemented by operation 1011 a.

In operation 1011 a, an RRC message including the carrier identifier ofthe first target uplink carrier is received from a target base station.

Exemplarily, the RRC message is information transmitted by the targetbase station to regulate and control resource configuration. After theterminal device accesses the target base station, before configuringother uplink resource or other downlink resource for the terminal deviceusing the RRC message, the target base station can configure a carrierused for initiating a random access for the terminal device in advance,thereby avoiding a failure in a random access caused by a situation thatthe terminal device cannot determine a carrier used to upload the randomaccess preamble when initiating the random access.

With two uplink carriers, i.e., one SUL carrier and one non-SUL carrier,included by the target base station as an example, the target basestation can determine random access resources included by the SULcarrier and the non-SUL carrier first, and then determine, according tothe random access resources included by the SUL carrier and the non-SULcarrier, the first target uplink carrier configured for the terminaldevice to initiate the random access, and notify the terminal device ofthe carrier identifier of the first target uplink carrier by includingthe carrier identifier of the first target uplink carrier in the RRCmessage transmitted to the terminal device. After receiving the RRCmessage, the terminal device can obtain a first carrier identifierincluded in the RRC message and determine, as the first target uplinkcarrier, a carrier with a carrier identifier same as the first carrieridentifier among the SUL carrier and the non-SUL carrier. In theembodiments of the disclosure, the carrier identifier of the firsttarget uplink carrier, which is included in the RRC message, isdesignated as the first carrier identifier for the purpose of easydifferentiation.

Specifically, a first function field can be added in the RRC message inadvance and pre-agreed between two sides: the terminal device and thetarget base station. After obtaining the first target uplink carrier,the target base station can write the first function field in thecarrier identifier of the first target uplink carrier. After receivingthe RRC message, the terminal device can parse the first function fieldto obtain the first carrier identifier and determine, as the firsttarget uplink carrier, a carrier that is in the SUL carrier and thenon-SUL carrier included by the target base station and corresponds tothe first carrier identifier.

In the technical solutions provided in the embodiments of thedisclosure, the terminal device can determine, according to theconfiguration of the target base station, the first target uplinkcarrier used for transmitting the random access preamble among theplurality of uplink carriers corresponding to the target base station,and transmit the random access preamble to the target base station usingthe first target uplink carrier to initiate the random access, so thatthe random access is implemented in cells configured with the SULcarrier, thus the success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG. 1d , theoperation 1011 of receiving a carrier identifier of a first targetuplink carrier from the base station can be implemented by operation1011 b.

In operation 1011 b, allocation information of a random access preambleis received from the target base station, the allocation information ofthe random access preamble including the carrier identifier of the firsttarget uplink carrier.

Exemplarily, the random access includes a competitive random access anda non-competitive random access. When triggering the non-competitiverandom access using a physical downlink control channel (PDCCH) command,the target base station can allocate the random access preamble to theterminal device according to a preset rule, and obtain, a carrier wherethe PDCCH is on among a plurality of uplink carriers, as the firsttarget uplink carrier configured for the terminal device to transmit therandom access preamble; the target base station can then generate theallocation information of the random access preamble according to therandom access preamble and the carrier identifier of the first targetuplink carrier, and transmit the allocation information of the randomaccess preamble to the terminal device. In the embodiments of thedisclosure, the carrier identifier of the first target uplink carrier,which is included in the allocation information of the random accesspreamble, is designated as a second carrier identifier for the purposeof easy differentiation.

After receiving the allocation information of the random accesspreamble, the terminal device can obtain the second carrier identifierincluded by the allocation information of the random access preamble,and obtain a carrier with a carrier identifier same as the secondcarrier identifier among the plurality of uplink carriers correspondingto the target base station, and the carrier is then first target uplinkcarrier configured for the terminal device to transmit the random accesspreamble by the target base station. At this time, the terminal devicecan initiate the random access using the first target uplink carrier totransmit the random access preamble allocated by the target base stationto the terminal device.

In a practical application, a function field can be added in theallocation information of the random access preamble to carry thecarrier identifier of the first target uplink carrier.

In the technical solutions provided in the embodiments of thedisclosure, the terminal device can determine, according to an advanceconfiguration of the target base station, the first target uplinkcarrier used for transmitting the random access preamble among theplurality of uplink carriers corresponding to the target base station,and transmit the random access preamble to the target base station usingthe first target uplink carrier to initiate the random access, so thatthe random access is implemented in cells configured with the SULcarrier, thus the success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG. 1e , theoperation 1011 of receiving a carrier identifier of a first targetuplink carrier transmitted by a base station can be implemented byoperation 1011 c.

In operation 1011 c, handover command information is received from anoriginal base station when the terminal device performs handover betweenthe original base station and the target base station, the handovercommand information including the carrier identifier of the first targetuplink carrier.

Exemplarily, two uplink carriers, i.e., an SUL carrier and a non-SULcarrier, included by the target base station will be described as anexample. When being used, the terminal device may perform the handoverto the target base station. When detecting that the terminal deviceneeds to perform the handover to the target base station, the originalbase station which the terminal device accesses currently can transmit ahandover request to the target base station which the terminal device isabout to access; after receiving the handover request, the target basestation can obtain, a carrier where the PDCCH is on among the SULcarrier and the non-SUL carrier, as the first target uplink carrierconfigured for the terminal device to transmit the random accesspreamble, generate handover request response information according tothe carrier identifier of first target uplink carrier, and transmit thehandover request response information to the original base station. In apractical application, the handover request response information canalso include the carrier identifier of the SUL carrier and carrieridentifier of the non-SUL carrier. The original base station cangenerate, according to the handover request response information, thehandover command information including the carrier identifier of the SULcarrier, the carrier identifier of the non-SUL carrier and the carrieridentifier of the first target uplink carrier, and transmit the handovercommand information to the terminal device. In the embodiments of thedisclosure, the carrier identifier of the first target uplink carrier,which is included in the handover command information, is designated asa third carrier identifier for the purpose of differentiation.

After receiving the handover command information from the original basestation, the terminal device obtains, a carrier with a carrieridentifier same as the third carrier identifier among the SUL carrierand the non-SUL carrier, as a carrier for transmitting the random accesspreamble, herein the carrier is the first target uplink carrierconfigured for the terminal device by the target base station.

Specifically, a fourth function field can be set in the handover requestresponse information in advance and pre-agreed between two sides: theoriginal base station and the target base station. The target basestation can write the carrier identifier of the first target uplinkcarrier into the fourth function field and the original base station canobtain the carrier identifier of the first target uplink carrier byparsing information in the fourth function field after receiving thehandover request response information. In the same way, a fifth functionfield can be configured in the handover command information and islocated in mobility control information of the handover commandinformation and pre-agreed between the two sides: the original basestation and the terminal device. The original base station can write thecarrier identifier of the first target uplink carrier into the fifthfunction field and after receiving the handover command information, theterminal device can obtain a fourth carrier identifier by parsinginformation of the fifth function field and the fourth carrieridentifier can be carrier identifier of the first target uplink carrierconfigured for the terminal device by the target base station.

In the technical solutions provided in the embodiments of thedisclosure, when being able to performing handover to the target basestation, the terminal device can determine, according to an advanceconfiguration of the target base station, the first target uplinkcarrier used for transmitting the random access preamble among theplurality of uplink carriers corresponding to the target base station,and transmit the random access preamble to the target base station usingthe first target uplink carrier to initiate a random access, so that therandom access is implemented in cells configured with the SUL carrier,thus the success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG, the operation1011 of receiving a carrier identifier of a first target uplink carrierfrom the base station can be implemented by operation 1011 d.

In operation 1011 d, a reconfiguration message is received from thetarget base station after the target base station re-establishes asecondary cell group (SCG) or modifies the SCG, the reconfigurationmessage including the carrier identifier of the first target uplinkcarrier.

Exemplarily, the target base station may re-establish or modify the SCGin the cells and may reconfigure a carrier used for transmitting arandom access preamble for a terminal device after re-establishing ormodifying the SCG because different SCGs maintain different resources.According to an embodiment of the disclosure, after re-establishing ormodifying the SCG, the target base station obtains, among a plurality ofuplink carriers, a carrier where a current PDCCH is on, as the firsttarget uplink carrier configured for the terminal device to transmit therandom access preamble. Because after the target base stationre-establishes or modifies the SCG, it needs to transmit areconfiguration message to the terminal device and notifies the terminaldevice of a latest resource configuration situation so that the carrieridentifier of the first target uplink carrier can be carried in thereconfiguration message to be transmitted to the terminal device. In theembodiments of the disclosure, the carrier identifier of the firsttarget uplink carrier, which is included in the reconfiguration message,is designated as a fourth carrier identifier for the purpose ofdifferentiation.

After receiving the reconfiguration message, the terminal device canobtain the fourth carrier identifier included in the reconfigurationmessage, and obtain, a carrier with a carrier identifier same as thefourth carrier identifier among the plurality of uplink carriers, as acarrier for transmitting the random access preamble, herein the carrieris the first target uplink carrier configured for the terminal device bythe target base station.

Specifically, a sixth function field can be set in the reconfigurationmessage and is located in the SCG of mobility control information andpre-agreed between the two sides: the terminal device and the targetbase station. When transmitting the reconfiguration message, the targetbase station can write the carrier identifier of the first target uplinkcarrier into the sixth function field and after receiving thereconfiguration message, the terminal device can obtain the fourthcarrier identifier by parsing information of the sixth function fieldand then the fourth carrier identifier is the carrier identifier of thefirst target uplink carrier.

In the technical solutions provided in the embodiments of thedisclosure, after the target base station re-establishes or modifies theSCG, the terminal device can determine, according to an advanceconfiguration of the target base station, the first target uplinkcarrier used for transmitting the random access preamble among theplurality of uplink carriers corresponding to the target base station,and transmit the random access preamble to the target base station usingthe first target uplink carrier to initiate a random access, so that therandom access is implemented in cells configured with the SUL carrier,thus the success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG. 1g , theoperation 101 of determining a first target uplink carrier among aplurality of uplink carriers corresponding to a target base station canbe implemented by operations 1013 to 1015.

In operation 1013, an RRC message including a power threshold isreceived from the target base station.

In operation 1014, a reference signal receiving power (RSRP) of acurrent downlink carrier is detected.

In operation 1015, the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the RSRP and the power threshold.

The target base station includes a plurality of uplink carriers and onedownlink carrier. During initialization, the target base station cantest a value of an attenuation limit of the downlink carriercorresponding to each uplink carrier when a location of the terminaldevice remains unchanged. With a reference uplink carrier as an example,when a current location of the terminal device remains unchanged, thetarget base station can test a relationship between an attenuationdegree of the downlink carrier and an attenuation degree of thereference uplink carrier, and determine the value of the attenuationlimit of the downlink carrier corresponding to the reference uplinkcarrier. If the attenuation of the downlink carrier is greater than thevalue of the attenuation limit, the attenuation of the reference uplinkcarrier is excessively great and information is not able to betransmitted to the target base station effectively; if the attenuationof the downlink carrier is less than or equal to the value of theattenuation limit, the attenuation of the reference uplink carrier issmall and reliability of uplink information can be ensured. Thereference uplink carrier is any one of the plurality of uplink carriers.

The target base station can divide cells it covers into several regions,determine the value of the attenuation limit of the downlink carriercorresponding to each uplink carrier when the terminal device is indifferent regions and store the value of the attenuation limit of thedownlink carrier corresponding to each uplink carrier according to eachregion. After the terminal device accesses the target base station, thetarget base station can obtain the value of the attenuation limit of thedownlink carrier corresponding to each uplink carrier in the regionwhere the terminal device is located, determine the power thresholdaccording to the value of the attenuation limit and notifies theterminal device of the power threshold by an RRC message, so that theterminal device can determine, in the region, the first target uplinkcarrier according to the power threshold and the RSRP of the currentdownlink carrier.

With two uplink carriers, i.e., one SUL carrier and one non-SUL,included by the target base station as an example, it is assumed that ina current region where the terminal device is located, the value of theattenuation limit of the downlink carrier corresponding to the non-SULcarrier is 30 dB and the value of the attenuation limit of the downlinkcarrier corresponding to the SUL carrier is 50 dB. That is to say, whenthe attenuation of the downlink carrier is 50 dB, the SUL carrier canstill ensure reliable data transmission, whereas when the attenuation ofthe downlink carrier is greater than 30 dB, the non-SUL carrier cannotensure the reliability of uplink data. As a result, the target basestation can set the power threshold of the terminal device in thecurrent region as 70 dB according to the value of the attenuation limitof the downlink carrier corresponding to the non-SUL carrier, whichmeans that when the RSRP of the received downlink carrier is less than70 dB, the attenuation of the downlink carrier is greater than 30 dB andwhen the RSRP of the received downlink carrier is greater than or equalto 70 dB, the attenuation of the downlink carrier is less than or equalto 30 dB. Then the target base station can notify the terminal device bythe RRC message. The terminal device stores the power threshold, andwhen the random access is needed to be initiated, the terminal devicefirst detects the RSRP of the current downlink carrier, which shows theattenuation degree of the downlink carrier, and then determines a valuerelationship between the RSRP and the power threshold. Specifically, thenon-SUL carrier is determined as the first target uplink carrier whenthe RSRP is greater than or equal to the power threshold, i.e., the RSRPis greater than or equal to 70 dB; the SUL carrier is determined as thefirst target uplink carrier when the RSRP is less than the powerthreshold, i.e., the RSRP is less than 70 dB.

Specifically, a second function field can be added in the RRC message inadvance and pre-agreed between the two sides: the terminal device andthe target base station. After obtaining the power threshold, the targetbase station can write the power threshold into the second functionfield. The terminal device can obtain the power threshold by parsing thesecond function field after receiving the RRC message.

In the technical solutions provided in the embodiments of thedisclosure, the terminal device can determine, according to a receivingpower of a reference signal of the downlink carrier and the powerthreshold configured in advance by the target base station, the firsttarget uplink carrier for transmitting a random access preamble amongthe plurality of uplink carriers corresponding to the target basestation, and transmit the random access preamble to the target basestation using the first target uplink carrier to initiate a randomaccess, so that the random access is implemented in cells configuredwith the SUL carrier, thus the success rate of the random access isincreased.

In an embodiment of the disclosure, as illustrated in the FIG. 1h , theoperation 101 of determining a first target uplink carrier among aplurality of uplink carriers corresponding to a target base station canbe implemented by operations 1016 to 1018.

In operation 1016, an RRC message including a quality threshold isreceived from the target base station.

In operation 1017, a reference signal receiving quality (RSRQ) of acurrent downlink carrier is detected.

In operation 1018, the first target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation according to the RSRQ and the quality threshold.

The target base station includes a plurality of uplink carriers and onedownlink carrier. During initialization, the target base station cantest a value of a quality limit of the downlink carrier corresponding toeach uplink carrier when a location of the terminal device remainsunchanged. With a reference uplink carrier as an example, when a currentlocation of the terminal device remains unchanged, the target basestation can test a relationship between the RSRQ of the downlink carrierand the RSRQ of the reference uplink carrier and determine the value ofthe quality limit of the downlink carrier. If the RSRQ of the downlinkcarrier is greater than or equal to the value of the quality limit, itmeans the reference uplink carrier has a better quality at this time andreliability of uplink information can be ensured; if the RSRQ of thedownlink carrier is less than the value of the quality limit, it meansthe reference uplink carrier has a worse quality at this time and theinformation may not be transmitted to the target base stationeffectively. The reference uplink carrier is any one of the plurality ofuplink carriers.

The target base station can divide cells it covers into several regions,determine the value of the quality limit of the downlink carriercorresponding to each uplink carrier when the terminal device is indifferent regions and store the value of the quality limit of thedownlink carrier corresponding to each uplink carrier according to eachregion. After the terminal device accesses the target base station, thetarget base station can obtain the value of the quality limit of thedownlink carrier corresponding to each uplink carrier in the regionwhere the terminal device is located, determine the quality thresholdaccording to the value of the quality limit and notifies the terminaldevice by an RRC message so that the terminal device can determine, inthe region, the first target uplink carrier according to the qualitythreshold and the RSRQ of the current downlink carrier.

With two uplink carriers, i.e., one SUL carrier and one non-SUL,included by the target base station as an example, suppose the terminaldevice is in a current region, and the value of the quality limit of thedownlink carrier corresponding to the SUL carrier is −10 and the valueof the quality limit of the downlink carrier corresponding to thenon-SUL carrier is −5, then it means when downlink carrier has a worsequality, the SUL carrier can still ensure reliable data transmission andwhile the RSRQ of the downlink carrier is less than −5, the non-SULcarrier cannot ensure the reliability of uplink data. As a result, thetarget base station can set the quality threshold of the terminal devicein the current region as −5 according to the value of the quality limitof the uplink carrier according to the non-SUL carrier and notify theterminal device by the RRC message. The terminal device stores thequality threshold and when the random access is needed to be initiated,the terminal device first detects the RSRQ of the current downlinkcarrier, and then determine a value relationship between the RSRQ andthe quality threshold. The non-SUL carrier is determined as the firsttarget uplink carrier when the RSRQ is greater than or equal to thequality threshold, which means the RSRQ is greater than or equal to −5;the SUL carrier is determined as the first target uplink carrier whenthe RSRQ is less than the quality threshold, which means the RSRQ of thedownlink carrier is less than −5.

Specifically, a third function field can be added in the RRC message inadvance and pre-agreed between two sides: the terminal device and thetarget base station. After obtaining the quality threshold, the targetbase station can write the quality threshold into the third functionthreshold and after receiving the RRC message, the terminal device canobtain the quality threshold by parsing the third function field.

In a practical application, the target base station can add the powerthreshold and the quality threshold in the RRC message at the same timeand transmit the RRC message to the terminal device. After receiving theRRC message, the terminal device stores the power threshold and thequality threshold. When a random access is needed, the terminal devicecan first detect the RSRP and the RSRQ of the current downlink carrierand then determine the first target uplink carrier among the pluralityof uplink carriers corresponding to the target base station according tothe RSRP and the power threshold as well as the RSRQ and the qualitythreshold. For example, the terminal device can determine the valuerelationship between the RSRP of the downlink carrier and the powerthreshold and the value relationship between the RSRQ and the qualitythreshold respectively. The non-SUL carrier is determined as the firsttarget uplink carrier in response to the RSRP being greater than orequal to the power threshold or in response to the RSRQ being greaterthan or equal to the quality threshold; and the SUL carrier isdetermined as the first target uplink carrier in response to the RSRPbeing less than the power threshold and the RSRQ being less than thequality threshold.

With two uplink carriers, i.e., one SUL carrier and one non-SUL,included by the target base station as an example, suppose the terminaldevice is in the current region, and the power threshold is set by thetarget base station as 70 dB and quality threshold is set as −5. Whenthe random access is needed, the terminal device can first detect theRSRP and the RSRQ of the downlink carrier. The non-SUL carrier isdetermined as the first target uplink carrier when the RSRP is greaterthan or equal to 70 dB or the RSRQ is greater than or equal to −5 andthe SUL carrier is determined as the first target uplink carrier whenthe RSRP is less than 70 dB or the RSRQ is less than −5.

In the technical solutions provided in the embodiments of thedisclosure, the terminal device can determine, according to a receivingquality of a reference signal of the downlink carrier and the qualitythreshold set in advance by the target base station, the first targetuplink carrier for transmitting a random access preamble among theplurality of uplink carriers corresponding to the target base station,and transmit the random access preamble to the target base station usingthe first target uplink carrier to initiate a random access, so that therandom access is implemented in cells configured with the SUL carrier,thus the success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in FIG. 1i , themethod also includes operations 103 to 105.

In operation 103, random access response information is received from atarget base station, the random access response information including acarrier identifier of a second target uplink carrier.

In operation 104, the second target uplink carrier is determined among aplurality of uplink carriers corresponding to the target base stationaccording to the carrier identifier of the second target uplink carrier.

In operation 105, scheduling transmission information is transmitted tothe target base station using the second target uplink carrier.

Exemplarily, after receiving a random access preamble from the terminaldevice, the target base station can transmit random access responseinformation to the terminal device. If a current random access is anon-competitive random access, the terminal device can implement therandom access according to the random access response information; ifthe current random access is a competitive random access, the terminaldevice needs to transmit the scheduled transmission information to thetarget base station according to the random access response informationand at this time the target base station can also configure, for theterminal device, the second target uplink carrier used for transmittingthe scheduled transmission information.

According to an embodiment of the disclosure, during the competitiverandom access, the target base station receives a random access preamblefrom the terminal device and can obtain a carrier, where a PDCCH is,from the plurality of uplink carriers corresponding to the target basestation and determine the carrier the second target uplink carrier usedby the terminal device to transmit the scheduled transmissioninformation and carry the carrier identifier of the second target uplinkcarrier in the random access response information and transmit therandom access response information to the terminal. In the embodimentsof the disclosure, the carrier identifier of the second target uplinkcarrier, which is included in the random access response information, isdesignated as a fifth carrier identifier for the purpose ofdifferentiation. After obtaining the random access response information,the terminal device obtains, a carrier with a carrier identifier same asthe fifth carrier identifier among the plurality of uplink carriers, asa carrier for transmitting the scheduled transmission information,herein the carrier is the second target uplink carrier configured forthe terminal device by the target base station. In a practicalapplication, the second target uplink carrier can be same as ordifferent from the first target uplink carrier. There are no limits madein the embodiments of the disclosure.

In the technical solutions provided in the embodiments of thedisclosure, the terminal device can determine, according toconfiguration of the target base station, the second target uplinkcarrier for transmitting the scheduled transmission information amongthe plurality of uplink carriers, and transmit the scheduledtransmission information to the target base station using the secondtarget uplink carrier, so that the random access based on a competitivemechanism is implemented in cells configured with the SUL carrier, thusthe success rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in the FIG. 1j , themethod also includes operations 106 and 107.

In operation 106, a third target uplink carrier is determined among aplurality of uplink carriers corresponding to a target base station ifrandom access response information is not received from the target basestation in a second preset period.

In operation 107, a random access preamble is transmitted to the targetbase station using the third target uplink carrier.

Exemplarily, if the terminal device does not receive the random accessresponse information from the target base station in the second presetperiod after transmitting a random access preamble to the target basestation, it means that the random access is unsuccessful and theterminal device can change the carrier for transmitting random accesspreamble. With two uplink carriers, i.e., one SUL carrier and onenon-SUL, included by the target base station as an example, suppose afirst target uplink carrier determined by the terminal device totransmit the random access preamble for the first time is the SULcarrier, if the random access response information is not received fromthe target base station in the second preset period, then terminaldevice can re-transmit the random access preamble to the target basestation using the non-SUL carrier which is the third target uplinkcarrier.

According to an embodiment of the disclosure, if the terminal devicetransmits the random access preamble to the target base station on thefirst target uplink carrier with a first transmitting power, then theterminal device can continue to transmit the random access preamble tothe target base station on the third target uplink carrier with thefirst transmitting power, which decreases losses of the terminaldevices.

In the technical solutions provided in the embodiments of thedisclosure, when the initiated random access is not responded, theterminal device can change the third target uplink carrier fortransmitting the random access preamble, and re-transmit the randomaccess preamble to the target base station using the third target uplinkcarrier, so that the success rate of the random access is increased.

Base Station Side

In the embodiments of disclosure, a random access method is provided andused in the base station which can transmit indication information tothe terminal device and the indication information is configured toindicate a first target uplink carrier to be determined, by the terminaldevice for transmitting a random access preamble, among a plurality ofuplink carriers corresponding to the base station, and the plurality ofuplink carriers include at least one SUL carrier.

Exemplarily, the indication information can be a carrier identifier of afirst target uplink carrier configured, by the base station, for theterminal device to transmit a random access preamble, and can also be apower threshold or a quality threshold configured, by the base station,for the terminal device.

With two uplink carriers, i.e., one SUL carrier and one non-SUL,included by the base station as an example, the base station can test avalue of an attenuation limit according to the SUL carrier and a valueof an attenuation limit according to the non-SUL carrier respectivelywhen a location of the terminal device remains unchanged. With thenon-SUL carrier as an example, when a current location of the terminaldevice remains unchanged, the base station can test a relationshipbetween an attenuation degree of the downlink carrier and an attenuationdegree of the non-SUL carrier and determine the value of the attenuationlimit of the downlink carrier. If the attenuation of the downlinkcarrier is greater than the value of the attenuation limit, then theattenuation of the non-SUL carrier is excessively great and informationis not able to be transmitted to the base station in an effective way;if the attenuation of the downlink carrier is less than or equal to thevalue of the attenuation limit, then attenuation of the non-SUL carrierat this time is smaller and reliability of uplink information can beensured. In the same way, the value of the attenuation limit of thedownlink carrier corresponding to the SUL carrier can be determined.

The base station can divide cells it covers into several regions,determine the value of the attenuation limit of the downlink carriercorresponding to the SUL carrier and the value of the attenuation limitof the downlink carrier corresponding to the non-SUL carrierrespectively when the terminal device is in different regions and storethe value of the attenuation limit of the downlink carrier correspondingto the SUL carrier and the value of the attenuation limit of thedownlink carrier corresponding to the non-SUL carrier according to eachregion. After the terminal device accesses the base station, the basestation can obtain, according to the region where the current terminaldevice is, the value of the attenuation limit of the downlink carriercorresponding to the SUL carrier and the value of the attenuation limitof the downlink carrier corresponding to the non-SUL carrier, determinea power threshold according to the value of the attenuation limit andnotifies the terminal device by an RRC message so that the terminaldevice in the region can determine the first target uplink carrieraccording to the power threshold and an RSRP of a current downlinkcarrier.

It is assumed that in a current region where the terminal device islocated, the value of the attenuation limit of the downlink carriercorresponding to the non-SUL carrier is 30 dB, and the value of theattenuation limit of the downlink carrier corresponding to the SULcarrier is 50 dB. That is to say, when the attenuation of the downlinkcarrier is 50 dB, the SUL carrier can still ensure reliable datatransmission and when the attenuation of the downlink carrier is greaterthan 30 dB, the non-SUL carrier cannot ensure reliability of uplinkdata. As a result, the base station can set, according to the value ofthe attenuation limit of the downlink carrier corresponding to thenon-SUL carrier, the power threshold of the terminal device in thecurrent region to 70 dB, which means that when the RSRP of the receiveddownlink carrier is less than 70 dB, the attenuation of the downlinkcarrier is greater than 30 dB; when the RSRP of the received downlinkcarrier is greater than or equal to 70 dB, the attenuation of thedownlink carrier is less than or equal to 30 dB. Then the base stationcan notify the terminal device of the power threshold by the RRCmessage. The terminal device stores the power threshold, and when therandom access is needed to be initiated, the terminal device firstdetects the RSRP of the current downlink carrier, which shows theattenuation degree of the downlink carrier, and then determines a valuerelationship between the RSRP and the power threshold. Specifically, thenon-SUL carrier is determined as the first target uplink carrier whenthe RSRP is greater than or equal to the power threshold, i.e., the RSRPis greater than or equal to 70 dB; the SUL carrier is determined as thefirst target uplink carrier when the RSRP is less than the powerthreshold, i.e., the RSRP is less than 70 dB.

According to an embodiment of the disclosure, the base station can testa value of quality limit of the downlink carrier corresponding to theSUL carrier and a value of quality limit of the downlink carriercorresponding to the non-SUL carrier respectively when the location ofthe terminal device remains unchanged. With the non-SUL carrier as anexample, the base station can test the relationship between an RSRQ ofthe downlink carrier and an RSRQ of the non-SUL carrier and determinethe value of the quality limit of the downlink carrier when the locationof the terminal device remains unchanged. If the RSRQ of the downlinkcarrier is greater than or equal to the value of the quality limit, itmeans that the non-SUL carrier has a better quality and the reliabilityof the uplink information can be ensured; if the RSRQ of the downlinkcarrier is less than the value of the quality limit, it means thatnon-SUL carrier has a worse quality and the information may not be ableto be transmitted to the base station. In the same way, the value of thequality limit of the downlink carrier according to the SUL carrier canbe tested.

The base station can divide cells it covers into several regions,determine the value of the quality limit of the downlink carriercorresponding to the SUL carrier and the value of the quality limit ofthe downlink carrier corresponding to the non-SUL carrier respectivelywhen the terminal device is in different regions and store the value ofthe quality limit of the downlink carrier corresponding to the SULcarrier and the value of the quality limit of the downlink carriercorresponding to the non-SUL carrier according to each region. After theterminal device accesses the base station, the base station can obtain,according to the region where the current terminal device is, the valueof the quality limit of the downlink carrier corresponding to the SULcarrier and the value of the quality limit of the downlink carriercorresponding to the non-SUL carrier, determine a quality thresholdaccording to the value of the quality limit and notifies the terminaldevice by the RRC message so that the terminal device in the region candetermine the first target uplink carrier according to the qualitythreshold and an RSRQ of the current downlink carrier.

It is assumed that in the current region where the terminal device islocated, the value of the quality limit of the downlink carriercorresponding to the SUL carrier is −10, and the value of theattenuation limit of the downlink carrier corresponding to the non-SULcarrier is −5. That is to say, when the downlink carrier has a worsequality, the SUL carrier can still ensure the reliable data transmissionand when RSRQ of the downlink carrier is less than −5, the non-SULcarrier cannot ensure the reliability of uplink data. As a result thebase station can set, according to the value of the quality limitcorresponding to the non-SUL carrier, the quality threshold of theterminal device in the current region to −5 and notify the terminaldevice of the quality threshold by the RRC message. The terminal devicestores the quality threshold and when the random access is needed to beinitiated, the terminal device first detects the RSRQ of the currentdownlink carrier, and then determine a value relationship between theRSRQ and the quality threshold. The non-SUL carrier is determined as thefirst target uplink carrier when the RSRQ is greater than or equal tothe quality threshold, which means the RSRQ is greater than or equal to−5; the SUL carrier is determined as the first target uplink carrierwhen the RSRQ is less than the quality threshold, which means the RSRQof the downlink carrier is less than −5.

In an embodiment of the disclosure, as illustrated in FIG. 2a , therandom access method includes the operations 201 to 202:

In operation 201, a first target uplink carrier configured for aterminal device to transmit a random access preamble is obtained among aplurality of uplink carriers.

Exemplarily, a base station can determine a carrier, where a PUCCH is,as the first target uplink carrier configured for the terminal device totransmit the random access preamble. If the base station configures thePUCCH on an SUL carrier, the SUL carrier can be configured as the firsttarget uplink carrier, and the terminal device can transmit the randomaccess preamble to the base station using the SUL carrier; if the basestation configures the PUCCH on an non-SUL carrier, the non-SUL carriercan be configured as the first target uplink carrier, and the terminaldevice can transmit the random access preamble to the base station usingthe non-SUL carrier; if the base station configures that the PUCCH canbe regulated dynamically on both the SUL carrier and the non-SULcarrier, then based on a time when a random access is initiated, thebase station can determine, as the first target uplink carrier, the SULcarrier or the non-SUL carrier where the PUCCH is on at the time whenthe random access is initiated.

Alternatively, the base station can obtain a random access resourceincluded by the SUL carrier and a random access resource included by thenon-SUL carrier respectively, and determine the first target uplinkcarrier according to the random access resource included by the SULcarrier and the random access resource included by the non-SUL carrier.For example, according to a time when the random access is initiated,the terminal device can obtain a carrier where an earliest-arrivingrandom access resource is on, and configure the obtained carrier as thefirst target uplink carrier, herein the earliest-arriving random accessresource is a random access resource that arrives at a time closest tothe time when the random access is initiated.

Alternatively, the base station can also evaluate a signal quality ofthe SUL carrier and a signal quality of the non-SUL carrier in advance,select a carrier with a better signal quality and configure the selectedcarrier as the first target uplink carrier. Specifically, the basestation can evaluate the signal quality of the SUL carrier and thesignal quality of the non-SUL carrier according to a number of lostpackets in a preset reference period. The less the packets are lost, thebetter the signal quality is.

In operation 202, a carrier identifier of the first target uplinkcarrier is transmitted to the terminal device to enable the terminaldevice to determine the first target uplink carrier among the pluralityof uplink carriers corresponding to the base station according to thecarrier identifier of the first target uplink carrier.

Exemplarily, after determining the first target uplink carrier needed tobe configured for the terminal device, the base station can transmit thecarrier identifier of the first target uplink carrier to the terminaldevice so that the terminal device can determine, among the SUL carrierand the non-SUL carrier, the first target uplink carrier configured bythe base station and transmit the random access preamble on the firsttarget uplink carrier.

In the technical solutions provided in the embodiments of thedisclosure, the base station can configure, among the plurality ofuplink carrier, configure the first target uplink carrier for theterminal device to transmit the random access preamble to enable theterminal device to transmit the random access preamble to the basestation using the first target uplink carrier to initiate the randomaccess, so that the random access is implemented in cells configuredwith the SUL carrier, thus the success rate of the random access isincreased.

In an embodiment of the disclosure, as illustrated in the FIG. 2b , theoperation 202 of transmitting a carrier identifier of a first targetuplink carrier to a terminal device can be implemented by operation2021.

In operation 2021, an RRC message including the carrier identifier ofthe first target uplink carrier is transmitted to the terminal device.

Exemplarily, the RRC message is information transmitted by a basestation to the terminal device to regulate and control resourceconfiguration. As a result, after the terminal device accesses the basestation, the base station can write the carrier identifier of the firsttarget uplink carrier into the RRC message and transmit the RRC messageto the terminal device while the base station configures other uplinkresource or downlink resource for the terminal device via the RRCmessage.

Specifically, a first function field can be added in the RRC message inadvance and pre-agreed between two sides: the terminal device and thebase station. After obtaining the first target uplink carrier, the basestation can write the carrier identifier of the first target uplinkcarrier into the first function field. After receiving the RRC message,the terminal device can obtain a first carrier identifier by parsing thefirst function field and determine, as the first target uplink carrier,a carrier corresponding to the first carrier identifier in the SUL andnon-SUL carrier included by the base station.

In the technical solutions provided in the embodiments of thedisclosure, the base station can configure, among a plurality of uplinkcarriers, the first target uplink carrier for the terminal device totransmit a random access preamble and notify the terminal device via theRRC message to enable the terminal device to transmit the random accesspreamble to the base station using the first target uplink carrier toinitiate a random access, so that the random access is implemented incells configured with the SUL carrier, thus the success rate of therandom access is increased.

In an embodiment of the disclosure, as illustrated in the FIG. 2c , theoperation 202 of transmitting a carrier identifier of a first targetuplink carrier to a terminal device can be implemented by operation2022.

In operation 2022, allocation information of a random access preamble istransmitted to the terminal device, the allocation information of therandom access preamble including the carrier identifier of the firsttarget uplink carrier.

Exemplarily, when triggering an non-competitive random access using aPDCCH command, the base station can allocate a random access preamble tothe terminal device according to a preset rule and concurrently obtain,among a plurality of uplink carriers, a carrier where the PDCCH is on,as the first target uplink carrier configured for the terminal device totransmit the random access preamble; the base station can then generatethe allocation information of the random access preamble according tothe random access preamble and the carrier identifier of the firsttarget uplink carrier, and transmit the allocation information of therandom access preamble to the terminal device.

In the technical solutions provided in the embodiments of thedisclosure, in the non-competitive random access, the base station canconfigure, among the plurality of uplink carriers, the first targetuplink carrier for the terminal device to transmit the random accesspreamble and notify the terminal device via the allocation informationof the random access preamble to enable to terminal device to transmitthe random access preamble to the base station using the first targetuplink carrier to initiate the random access, so that the random accessis implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

In an embodiment of the disclosure, as illustrated in the FIG. 2d , theoperation 201 of obtaining, among a plurality of uplink carriers, afirst target uplink carrier configured for a terminal device to transmita random access preamble can be implemented by operations 2011 and 2012;the operation 202 of transmitting a carrier identifier of the firsttarget uplink carrier to the terminal device can be implemented byoperation 2023.

In operation 2011, a handover request is received from an original basestation, the handover request indicating that the terminal deviceperforms handover from the original base station to the base station.

In operation 2012, the first target uplink carrier configured for theterminal device to transmit the random access preamble among theplurality of uplink carriers is obtained according to the handoverrequest.

In operation 2023, handover response information is transmitted to theoriginal base station, the handover response information including thecarrier identifier of the first target uplink carrier to enable theoriginal base station to transmit, to the terminal device, handovercommand information including the carrier identifier of the first targetuplink carrier.

Exemplarily, during usage, the terminal device may perform handoverbetween the base stations. When detecting that the terminal devicesneeds to perform the handover between the base stations, an originalbase station accessed currently by the terminal device can transmit ahandover request to a base station that the terminal device is about toaccess. After receiving the handover, the base station can obtain, amongan SUL carrier and a non-carrier carrier, a carrier where a PDCCH is on,as the first target uplink carrier configured for the terminal device totransmit a random access preamble; and then generate handover requestresponse information according to a carrier identifier of the firsttarget uplink carrier, and transmit the handover request responseinformation to the original base station. In a practical application,the handover request response information also includes the carrieridentifier of the SUL carrier and the carrier identifier of the non-SULcarrier. The original base station can generate handover commandinformation according to the handover request response information andthe handover command information includes the carrier identifier of theSUL carrier, the carrier identifier of the non-SUL carrier and thecarrier identifier of the first target uplink carrier and transmit thehandover command information to the terminal device.

In a practical application, a function field can be added in thehandover request response information and the handover commandinformation. Then the function field can be configured to carry thecarrier identifier of the first target uplink carrier.

In the technical solutions provided in the embodiments of thedisclosure, when the terminal device performs the handover between thebase stations, the base station can configure, among the plurality ofuplink carriers, the first target uplink carrier for the terminal deviceto transmit the random access preamble and notify the original basestation via the handover response information, so that the original basestation can notify the terminal device and the random access isimplemented in cells configured with the SUL carrier, thus the successrate of the random access is increased.

In an embodiment of the disclosure, as illustrated in the FIG. 2e , theoperation 202 of transmitting a carrier identifier of a first targetuplink carrier to a terminal device can be implemented by operation2024.

In operation 2024, after re-establishing or modifying an SCG, a basestation transmits a reconfiguration message to the terminal device andthe reconfiguration message including the carrier identifier of thefirst target uplink carrier.

Exemplarily, the base station may re-establish or modify the SCG in thecells and may reconfigure a carrier used for transmitting a randomaccess preamble for a terminal device after re-establishing or modifyingthe SCG because different SCGs maintain different resources. Accordingto an embodiment of the disclosure, after re-establishing or modifyingthe SCG, the base station obtains, among the SUL carrier and non-SULcarrier, a carrier where a current PDCCH is on and configures theobtained carrier as the first target uplink carrier for the terminaldevice to transmit a random access preamble. Because afterre-establishing or modifying the SCG, the base station needs to transmitthe reconfiguration message to the terminal device to notify theterminal device of a latest resource configuration situation. As aresult, the base station can carry the carrier identifier of the firsttarget uplink carrier in the reconfiguration message and transmit thereconfiguration message to the terminal device.

In the technical solutions provided in the embodiments of thedisclosure, when re-establishing or modifying the SCG, the base stationnotifies the terminal device, via the reconfiguration message, of thefirst target uplink carrier configured for the terminal device totransmit the random access preamble, so that the random access isimplemented in cells configured with the SUL carrier, thus the successrate of the random access is increased.

In an embodiment of the disclosure, as illustrated in the FIG. 2f , themethod further includes operations 203 and 204.

In operation 203, a second target uplink carrier configured for aterminal device to transmit scheduled transmission information isobtained among a plurality of uplink carriers according to a randomaccess preamble transmitted by the terminal device.

In operation 204, random access response information is transmitted tothe terminal device, the random access response information includingthe carrier identifier of the second target uplink carrier.

Exemplarily, during a competitive random access, the base stationreceives the random access preamble from the terminal from the terminaldevice and can obtain, among an SUL carrier and a non-SUL carrier, acarrier where a PDCCH is on, as the second target uplink carrier used bythe terminal device to transmit scheduled transmission information, andthen carry the carrier identifier of the second target uplink carrier inthe random access response information, and notify the terminal deviceof the random access response information. After obtaining the randomaccess response information, the terminal device obtains, among the SULcarrier and the non-SUL carrier, a carrier with a carrier identifiersame as the carrier identifier included by the random access responseinformation, as a carrier for transmitting the scheduled transmissioninformation, herein the carrier is the second target uplink carrierconfigured for the terminal device by the base station. In a practicalapplication, the second target uplink carrier can be same as ordifferent from the first target uplink carrier. There are no limits madein the embodiments of the disclosure.

In the technical solutions provided in the embodiments of thedisclosure, the base station can also configure the second target uplinkcarrier for the terminal device to transmit the scheduled transmissionmessage and notify the terminal device via the random access responseinformation, so that the random access is implemented in cellsconfigured with the SUL carrier, thus the success rate of the randomaccess is increased.

The technical solutions in the embodiments of the disclosure will bedescribed below by means of a specific embodiment of the disclosure.

First Embodiment

FIG. 3 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment. The random access method isapplied to a terminal device and a base station, herein the base stationincludes: two uplink carriers including one SUL carrier and one non-SULcarrier, and one downlink carrier. As illustrated in FIG. 3, the methodincludes the following operations 301 to 311.

In operation 301, the base station broadcasts a system message.

The system information includes a carrier identifier of the SUL carrier,a carrier identifier of the non-SUL carrier and a carrier identifier ofthe downlink carrier. Usually, the carrier identifier of the SUL carriercan be a frequency of the SUL carrier and the carrier identifier of thenon-SUL carrier can be a frequency of the non-SUL carrier and thecarrier identifier of the downlink carrier can be a frequency of thedownlink carrier.

In operation 302, the terminal device accesses the base stationaccording to the system message.

In operation 303, when the terminal device is in a connected state andan uplink out-of-synchronization situation exists, the base stationallocate a random access preamble to the terminal device, obtain, amongthe two uplink carriers, a carrier where a PUCCH is on, as the firsttarget uplink carrier.

In operation 304, the base station generates allocation information ofthe random access preamble according to the random access preamble andthe carrier identifier of the first target uplink carrier.

In operation 305, the base station transmits the allocation informationof the random access preamble to the terminal device.

In operation 306, the terminal device obtains the carrier identifierincluded by the allocation information of the random access preamble.

Exemplarily, the carrier identifier can be a carrier frequency.

In operation 307, the terminal device obtains, as the first targetuplink carrier, a carrier corresponding to the carrier identifier amongthe SUL carrier and the non-SUL carrier.

In operation 308, the terminal device transmits the random accesspreamble to the base station using the first target uplink carrier.

If the random access response information is not received from the basestation in a second preset period, the terminal device transmits therandom access preamble using another uplink carrier other than the firsttarget uplink carrier. Exemplarily, a transmitting power with which theterminal transmits the random access preamble for the second time can besame as the transmitting power with which the terminal transmits therandom access preamble for the first time.

In operation 309, the base station generates the random access responseinformation according to the random access preamble.

In operation 310, the base station transmits the random access responseinformation to the terminal device.

In operation 311, the terminal device initiates a random accessaccording to the random access response information.

In a random access method provided in the embodiments of the disclosure,the base station can configure the first target uplink carrier for theterminal device to transmit the random access preamble and notify theterminal device via the allocation information of the random accesspreamble when the base station is in the uplink out-of-synchronizationsituation. The terminal device can transmit, on the first target uplinkcarrier, the random access preamble to a target base station accordingto configuration of the base station, so that the random access isimplemented in cells configured with the SUL carrier, thus the successrate of the random access is increased.

Second Embodiment

FIG. 4 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment. The random access method isapplied to a terminal device, an original base station and a target basestation, herein the target base station includes: two uplink carriersincluding one SUL carrier and one non-SUL carrier, and one downlinkcarrier. As illustrated in FIG. 4, the method includes the followingoperations 401 to 417.

In operation 401, if it is detected that the terminal device needs toperform handover to the target base station, the original base stationtransmits a handover request to the target base station.

In operation 402, the target base station obtains a random accessresource of an SUL carrier and a random access resource of a non-SULcarrier respectively according to the handover request.

In operation 403, the target base station determines a first targetuplink carrier configured for the terminal device according to therandom access resource of the SUL carrier and the random access resourceof the non-SUL carrier.

In operation 404, the target base station generates handover responseinformation according to a carrier identifier of the first target uplinkcarrier and a carrier identifier of the SUL carrier and a carrieridentifier of the non-SUL carrier.

In operation 405, the target base station transmits the handoverresponse information to the original base station.

In operation 406, the original base station generates handover commandinformation according to the carrier identifier of the first targetuplink carrier and the carrier identifier of the SUL carrier and thecarrier identifier of the non-SUL carrier included by the handoverresponse information.

In operation 407, the original base station transmits the handovercommand information to the terminal.

In operation 408, after performing the handover to the target basestation, if the terminal device determines to initiate a random access,the terminal device determines, among the SUL carrier and the non-SULcarrier included by the target base station, an uplink carrier with thecarrier identifier same as the carrier identifier of the first targetuplink carrier included in the handover command information as the firsttarget uplink carrier.

In operation 409, the terminal device transmits a random access preambleto the target base station using the first target uplink carrier.

If random access response information is not received from the basestation in a second preset period, the terminal device transmits therandom access preamble using another uplink carrier other than the firsttarget uplink carrier.

In operation 410, according to the random access preamble, the targetbase station determines, among the SUL carrier and the non-SUL carrier,a carrier where a PUCCH is as a second target uplink carrier.

In operation 411, the target base station generates random accessresponse information according to the carrier identifier of the secondtarget uplink carrier.

In operation 412, the target base station transmits the random accessresponse information to the terminal device.

In operation 413, the terminal device determines, among the SUL carrierand the non-SUL carrier, an uplink carrier corresponding to the carrieridentifier included by the random access response information as thesecond target uplink carrier.

In operation 414, the terminal device transmits scheduled transmissioninformation to the target base station using the second target uplinkcarrier.

In operation 415, the target base station generates conflict-solvinginformation according to the scheduled transmission information.

In operation 416, the target base station transmits the conflict-solvinginformation to the terminal device.

In operation 417, the terminal device implements the random accessaccording to the conflict-solving information.

In a random access method provided in the embodiments of the disclosure,the target base station can configure the first target uplink carrierfor the terminal device to transmit the random access preamble andnotifies the terminal device via allocation information of the randomaccess preamble when the terminal device performs the handover betweenthe base stations. The terminal device can transmit, on the first targetuplink carrier, the random access preamble to the target base stationaccording to configuration of the base station, so that the randomaccess is implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

Third Embodiment

FIG. 5 is an interaction diagram illustrating a random access methodaccording to an exemplary embodiment. The random access method isapplied to a terminal device and a base station, herein the base stationincludes: two uplink carriers including one SUL carrier and one non-SULcarrier, and one downlink carrier. As illustrated in FIG. 5, the methodincludes the following operations 501 to 516.

In operation 501, the base station broadcasts a system message.

The system information includes a carrier identifier of the SUL carrier,a carrier identifier of the non-SUL carrier and a carrier identifier ofthe downlink carrier. Usually, the carrier identifier of the SUL carriercan be a frequency of the SUL carrier and the carrier identifier of thenon-SUL carrier can be a frequency of the non-SUL carrier and thecarrier identifier of the downlink carrier can be a frequency of thedownlink carrier.

In operation 502, the terminal device accesses the base stationaccording to the system message.

In operation 503, if the base station re-establishes or modifies an SCGfor a current cell, the base station obtain a random access resourceincluded by the SUL carrier and a random access resource included by thenon-SUL carrier after the re-establishment or the modification.

In operation 504, the base station obtains a first target uplink carrierconfigured for the terminal device according to the random accessresource included by the SUL carrier and the random access resourceincluded by the non-SUL carrier.

In operation 505, the base station generates a reconfiguration messageaccording to the carrier identifier of the first target uplink carrier.

In operation 506, the base station transmits the reconfiguration messageto the terminal device.

In operation 507, the terminal device obtains, among the SUL carrier andthe non-SUL carrier, a carrier corresponding to the carrier identifierincluded in the reconfiguration message, as the first target uplinkcarrier.

In operation 508, when a random access is needed, the terminal devicetransmit a random access preamble to the base station using the firsttarget uplink carrier.

If random access response information is not received from the basestation in a second preset period, the terminal device transmits therandom access preamble using another uplink carrier other than the firsttarget uplink carrier.

In operation 509, according to the random access preamble, the basestation determines, among the SUL carrier and the non-SUL carrier, acarrier where a PUCCH is as a second target uplink carrier.

In operation 510, the base station generates random access responseinformation according to the carrier identifier of the second targetuplink carrier.

In operation 511, the base station transmits the random access responseinformation to the terminal device.

In operation 512, the terminal device determines, as the second targetuplink carrier, an uplink carrier corresponding to the carrieridentifier included by the random access response information.

In operation 513, the terminal device transmits scheduled transmissioninformation to the base station using the second target uplink carrier.

In operation 514, the base station generates conflict-solvinginformation according to the scheduled transmission information.

In operation 515, the base station transmits the conflict-solvinginformation to the terminal device.

In operation 516, the terminal device implements a random accessaccording to the conflict-solving information.

In a random access method provided in the embodiments of the disclosure,a target base station can configure the first target uplink carrier forthe terminal device to transmit the random access preamble and notifythe terminal device via allocation information of the random accesspreamble when the terminal device performs handover between the basestations. The terminal device can transmit, on the first target uplinkcarrier, the random access preamble to the target base station accordingto configuration of the base station, so that the random access isimplemented in cells configured with the SUL carrier, thus the successrate of the random access is increased.

The device embodiments of the disclosure below can be used to implementthe method embodiments of the disclosure.

FIG. 6a is a block diagram illustrating a random access device 60according to an exemplary embodiment and the device 60 can beimplemented and become a part or all of an electrical device viasoftware, hardware or a combination of the software and the hardware. Asillustrated in FIG. 6a , the random access device 60 includes a firstdetermination module 601 and a first transmitting module 602.

The first determination module 601 is configured to determine a firsttarget uplink carrier among a plurality of uplink carriers correspondingto a target base station, the plurality of uplink carriers including atleast one SUL carrier.

The first transmitting module 602 is configured to transmit a randomaccess preamble to the target base station using the first target uplinkcarrier.

In an embodiment of the disclosure, as illustrated in FIG. 6b , thefirst determination module 601 includes a first receiving sub-module6011 and a first determination sub-module 6012.

The first receiving sub-module 6011 is configured to receive a carrieridentifier of the first target uplink carrier from a base station.

The first determination sub-module 6012 is configured to determine thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 6c , thefirst receiving sub-module 6011 includes a first receiving unit 6011 a.The first receiving unit 6011 a is configured to receive an RRC messagefrom the target base station, the RRC message including the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 6d , thefirst receiving sub-module 6011 includes a second receiving unit 6011 b.The second receiving unit 6011 b is configured to receive allocationinformation of the random access preamble from the target base station,the random access preamble including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 6e , thefirst receiving sub-module 6011 includes a third receiving unit 6011 c.The third receiving unit 6011 c is configured to receive handovercommand information from an original base station when the terminaldevice performs handover between the original base station and thetarget base station, the handover command information including thecarrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 6f , thefirst receiving sub-module 6011 includes a fourth receiving unit 6011 d.The fourth receiving unit 6011 d is configured to receive areconfiguration message from the target base station after the targetbase station re-establishes an SCG or modifies the SCG, thereconfiguration message including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 6g , thefirst determination module 601 includes a second receiving sub-module6013, a first detection sub-module 6014 and a second determinationsub-module 6015.

The second receiving sub-module 6013 is configured to receive an RRCmessage including a power threshold from the target base station.

The first detection sub-module 6014 is configured to detect an RSRP of acurrent downlink carrier.

The second determination sub-module 6015 is configured to determine thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station, according to the RSRP and thepower threshold.

In an embodiment of the disclosure, as illustrated in FIG. 6h , theplurality of uplink carriers includes one SUL carrier and one non-SULcarrier; the second determination sub-module 6015 includes a firstdetermination unit 6015 a and a second determination unit 6015 b.

The first determination unit 6015 a is configured to determine thenon-SUL carrier as the first target uplink carrier in response to theRSRP being greater than or equal to the power threshold.

The second determination unit 6015 b is configured to determine the SULcarrier as the first target uplink carrier in response to the RSRP beingless than the power threshold.

In an embodiment of the disclosure, as illustrated in FIG. 6i , thefirst determination module 601 includes a third receiving sub-module6016, a second detection sub-module 6017 and a third determinationsub-module 6018.

The third receiving sub-module 6016 is configured to receive an RRCmessage including a quality threshold from the target base station.

The second detection sub-module 6017 is configured to detect an RSRQ ofthe current downlink carrier.

The third determination sub-module 6018 is configured to determine thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRQ and thequality threshold.

In an embodiment of the disclosure, as illustrated in FIG. 6j , theplurality of uplink carriers includes on SUL carrier and one non-SULcarrier; the third determination sub-module 6018 includes a thirddetermination unit 6018 a and a fourth determination unit 6018 b.

The third determination unit 6018 a is configured to determine thenon-SUL carrier as the first target uplink carrier in response to theRSRQ being greater than or equal to the quality threshold.

The fourth determination unit 6018 b is configured to determine the SULcarrier as the first target uplink carrier in response to the RSRQ beingless than the quality threshold.

In an embodiment of the disclosure, as illustrated in FIG. 6k , thefirst determination module 601 includes a fourth receiving sub-module6019, a third detection sub-module 6110 and a fourth determinationsub-module 6011.

The fourth receiving sub-module 6019 is configured to receive, from thetarget base station, an RRC message including a power threshold and aquality threshold.

The third detection sub-module 6110 is configured to detect the RSRP andthe RSRQ of the current downlink carrier.

The fourth determination sub-module 6011 is configured to determine thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of uplink carriersincludes one SUL and one non-SUL. As illustrated in FIG. 6l , the fourthdetermination sub-module 6111 includes a fifth determination unit 6111 aand a sixth determination unit 6111 b.

The fifth determination unit 6111 a is configured to determine thenon-SUL carrier as the first target uplink carrier when the RSRP isgreater than or equal to the power threshold, or the RSRQ is greaterthan or equal to the quality threshold.

The sixth determination unit 6111 b is configured to determine the SULcarrier as the first target uplink carrier in response to the RSRP beingless than the power threshold and the RSRQ being less than the qualitythreshold.

In an embodiment of the disclosure, as illustrated in FIG. 6m , thefirst determination module 601 includes a fifth determination sub-module6112 configured to determine, as the first target uplink carrier, acarrier configured with a PUCCH among the plurality of uplink carriers.

In an embodiment of the disclosure, as illustrated in FIG. 6n , thefirst determination module 601 includes a sixth determination sub-module6113. The sixth determination sub-module 6113 is configured to determinethe first target uplink carrier according to a random access resourceincluded by each of the plurality of uplink carriers.

In an embodiment of the disclosure, as illustrated in FIG. 6o , thedevice 60 further includes a receiving module 603, a seconddetermination module 604 and a second transmitting module 605.

The receiving module 603 is configured to receive random access responseinformation from the target base station, the random access responseinformation including a fifth carrier identifier.

The second determination module 604 is configured to determine a secondtarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the fifth carrieridentifier.

The second transmitting module 605 is configured to transmit scheduledtransmission information to the target base station using the secondtarget uplink carrier.

The above embodiment of the disclosure is also suitable for the randomaccess device 60 illustrated in FIG. 6a to FIG. 6 n.

In an embodiment of the disclosure, as illustrated in FIG. 6p , thedevice 60 further includes a third determination module 606 and a thirdtransmitting module 607.

The third determination module 606 is configured to determine a thirdtarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station if the random access responseinformation is not received from the target base station in a secondpreset period.

The third transmitting module 607 is configured to transmit the randomaccess preamble to the target base station using the third target uplinkcarrier.

The above embodiment of the disclosure is also suitable for the randomaccess device 60 illustrated in FIG. 6a to FIG. 6 n.

In an embodiment of the disclosure, as illustrated in FIG. 6q , thethird transmitting module 607 includes a first obtaining sub-module 6071and a first transmitting sub-module 6072.

The first obtaining sub-module 6071 is configured to obtain atransmitting power with which the random access preamble is transmittedto the target base station using the first target uplink carrier.

The first transmitting sub-module 6072 is configured to transmit therandom access preamble to the target base station on the third targetuplink carrier with the transmitting power.

A random access device is provided in the embodiments of the disclosureand the device can determine, among the plurality of uplink carrierscorresponding to the target base station, the first target uplinkcarrier used for transmitting the random access preamble and transmitthe random access preamble to the target base station using the firsttarget uplink carrier to initiate a random access, so that the randomaccess is implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

FIG. 7a is a block diagram illustrating a random access device 70according to an exemplary embodiment and the device 70 can beimplemented and become a part or all of an electrical device viasoftware, hardware or a combination of the software and the hardware.According to FIG. 7a , the random access device 70 includes a fourthtransmitting module 701.

The fourth transmitting module 701 is configured to transmit indicationinformation to a terminal device, the indication information beingconfigured to indicate a first target uplink carrier to be determined,by the terminal device for transmitting a random access preamble, amonga plurality of uplink carriers corresponding to the base station, andthe plurality of uplink carriers including at least one SUL carrier.

In an embodiment of the disclosure, as illustrated in FIG. 7b , thedevice 70 also includes a first obtaining module 702 and the fourthtransmitting module includes a first transmitting sub-module 7011.

The first obtaining module 702 is configured to obtain the first targetuplink carrier, configured for the terminal device to transmit therandom access preamble, among the plurality of uplink carriers.

The first transmitting sub-module 7011 is configured to transmit acarrier identifier of the first target uplink carrier to the terminaldevice to enable the terminal device to determine the first targetuplink carrier among the plurality of uplink carriers corresponding tothe base station according to the carrier identifier of the first targetuplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 7c , thesecond obtaining sub-module 7021 is configured to obtain the firsttarget uplink carrier configured for the terminal device to transmit therandom access preamble according to a random access resource included byeach of the plurality of uplink carriers.

In an embodiment of the disclosure, as illustrated in FIG. 7d , thefirst transmitting sub-module 7011 includes a first transmitting unit7011 a configured to transmit an RRC message to the terminal device, theRRC message including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, as illustrated in FIG. 7e , thefirst transmitting sub-module 7011 includes a second transmitting unit7011 b configured to transmit allocation information of the randomaccess preamble to the terminal device, the allocation information ofthe random access preamble including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 7f , thefirst obtaining module 702 includes a seventh receiving sub-module 7022and a third obtaining sub-module 7023; and the first transmittingsub-module 7011 includes a third transmitting unit 7011 c.

The seventh receiving sub-module 7022 is configured to receive ahandover request from an original base station, the handover requestindicating that the terminal device performs a handover from theoriginal base station to the base station.

The third obtaining sub-module 7023 is configured to obtain the firsttarget uplink carrier, configured for the terminal device to transmitthe random access preamble, among the plurality of uplink carriersaccording to the handover request.

The third transmitting unit 7011 c is configured to transmit handoverresponse information to the original base station, the handover responseinformation including the carrier identifier of the first target uplinkcarrier to enable the original base station to transmit handover commandinformation including the carrier identifier of the first target uplinkcarrier to the terminal device.

In an embodiment of the disclosure, as illustrated in FIG. 7g , thefirst transmitting sub-module 7011 includes a fourth transmitting unit7111 d. The fourth transmitting unit 7111 d is configured to transmitreconfiguration information to the terminal device after the basestation re-establishes an SCG or modifies the SCG, the reconfigurationinformation including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, as illustrated in FIG. 7h , thefourth transmitting module includes a second transmitting sub-module7012. The second transmitting sub-module 7012 is configured to transmita power threshold to the terminal device to enable the terminal deviceto determine the first target uplink carrier for transmitting the randomaccess preamble, among the plurality of uplink carriers corresponding tothe base station, according to the power threshold and an RSRP of acurrent downlink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 7i , thefourth transmitting module 701 includes a third transmitting sub-module7013 configured to transmit a quality threshold to the terminal deviceto enable the terminal device to determine the first target uplinkcarrier for transmitting the random access preamble, among the pluralityof uplink carriers corresponding to the base station, according to thequality threshold and an RSRQ of a current downlink carrier.

In an embodiment of the disclosure, as illustrated in FIG. 7j , thedevice 70 further includes a second obtaining module 703 and a fifthtransmitting module 704.

The second obtaining module 703 is configured to obtain the secondtarget uplink carrier, configured for the terminal device to transmitscheduled transmission information, among the plurality of uplinkcarriers according to the random access preamble transmitted by theterminal device.

The fifth transmitting module 704 is configured to transmit randomaccess response information to the terminal device, the random accessresponse information including the carrier identifier of the secondtarget uplink carrier.

The above embodiment of the disclosure is also suitable for the randomaccess device 70 illustrated in FIG. 7a to FIG. 7 i.

A random access device is provided in the embodiments of the disclosureand the device can determine, among the plurality of uplink carriers,the first target uplink carrier for transmitting the random accesspreamble and transmit the random access preamble to the target basestation using the first target uplink carrier, so that the random accessis implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

The embodiments of the disclosure further provide a random access devicewhich includes:

a first processor;

a first memory configured to store instructions executable by the firstprocessor;

The first processor is configured to:

determine a first target uplink carrier among a plurality of uplinkcarriers corresponding to a target base station, the plurality of uplinkcarriers including at least one SUL carrier; and

transmit a random access preamble to the target base station using thefirst target uplink carrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive a carrier identifier of the first target uplinkcarrier from the base station and determine the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station according to the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive an RRC message including the carrier identifier ofthe first target uplink carrier from the target base station.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive allocation information of the random accesspreamble from the target base station, the random access preambleincluding the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive handover command information from an original basestation when the terminal device performs handover between the originalbase station and the target base station, the handover commandinformation including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive a reconfiguration message from the target basestation after the target base station re-establishes an SCG or modifiesthe SCG, the reconfiguration message including the carrier identifier ofthe first target uplink carrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive an RRC message including a power threshold fromthe target base station, detect an RSRP of a current downlink carrierand determine the first target uplink carrier among the plurality ofuplink carriers corresponding to the target base station, according tothe RSRP and the power threshold.

In an embodiment of the disclosure, the plurality of uplink carriersinclude one SUL carrier and one non-SUL carrier; the above firstprocessor is also configured to determine the non-SUL carrier as thefirst target uplink carrier in response to the RSRP being greater thanor equal to the power threshold, and determine the SUL carrier as thefirst target uplink carrier in response to the RSRP being less than thepower threshold.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive an RRC message including a quality threshold fromthe target base station, detect the RSRQ of the current downlink carrierand determine the first target uplink carrier among the plurality ofuplink carriers corresponding to the target base station, according tothe RSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of uplink carriersinclude one SUL carrier and one non-SUL carrier; the above firstprocessor is also configured to determine the non-SUL carrier as thefirst target uplink carrier in response to the RSRQ being greater thanor equal to the quality threshold, and determine the SUL carrier as thefirst target uplink carrier in response to the RSRQ being less than thequality threshold.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive, from the target base station, an RRC messageincluding the power threshold and the quality threshold, detect the RSRPand the RSRQ of the current downlink carrier and determine the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of uplink carriersinclude one SUL carrier and one non-SUL carrier; the above firstprocessor is also configured to determine the non-SUL carrier as thefirst target uplink carrier when the RSRP is greater than or equal tothe power threshold, or the RSRQ is greater than or equal to the qualitythreshold; and determine the SUL carrier as the first target uplinkcarrier when the RSRP is less than the power threshold and the RSRQ isless than the quality threshold.

In an embodiment of the disclosure, the above first processor is alsoconfigured to determine, as the first target uplink carrier, a carrierconfigured with a PUCCH among the plurality of uplink carriers.

In an embodiment of the disclosure, the above first processor is alsoconfigured to determine the first target uplink carrier according to arandom access resource included by each of the plurality of uplinkcarriers.

In an embodiment of the disclosure, the above first processor is alsoconfigured to receive, from the target base station, random accessresponse information including the carrier identifier of a second targetuplink carrier, determine, according to the carrier identifier of thesecond target uplink carrier, the second target uplink carrier among theplurality of uplink carriers corresponding to the target base stationand transmit scheduled transmission information to the target basestation using the second target uplink carrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to determine a third target uplink carrier among theplurality of uplink carriers corresponding to the target base station ifthe random access response information is not received from the targetbase station in a second preset period and transmit the random accesspreamble to the target base station using the third target uplinkcarrier.

In an embodiment of the disclosure, the above first processor is alsoconfigured to obtain a transmitting power with which the random accesspreamble is transmitted to the target base station using the firsttarget uplink carrier and transmit the random access preamble to thetarget base station on the third target uplink carrier with thetransmitting power.

A random access device is provided in the embodiments of the disclosureand the device can determine, among the plurality of uplink carrierscorresponding to the target base station, the first target uplinkcarrier used for transmitting the random access preamble and transmitthe random access preamble to the target base station using the firsttarget uplink carrier to initiate a random access, so that the randomaccess is implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

The embodiments of the disclosure further provide a random access devicewhich includes:

a second processor;

a second memory configured to store instructions executable by thesecond processor;

The second processor is configured to:

transmit indication information to a terminal device, the indicationinformation being configured to indicate a first target uplink carrierto be determined, by the terminal device for transmitting a randomaccess preamble, among a plurality of uplink carriers corresponding to abase station, and the plurality of uplink carriers including at leastone SUL carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to obtain the first target uplink carrier, configured for theterminal device to transmit the random access preamble, among theplurality of uplink carriers and transmit a carrier identifier of thefirst target uplink carrier to the terminal device to enable theterminal device to determine the first target uplink carrier among theplurality of uplink carriers corresponding to the base station accordingto the carrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to obtain the first target uplink carrier configured for theterminal device to transmit the random access preamble according to arandom access resource included by each of the plurality of uplinkcarriers.

In an embodiment of the disclosure, the above second processor is alsoconfigured to transmit an RRC message including the carrier identifierof the first target uplink carrier to the terminal device.

In an embodiment of the disclosure, the above second processor is alsoconfigured to transmit allocation information of the random accesspreamble to the terminal device, the allocation information of therandom access preamble including the carrier identifier of the firsttarget uplink carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to receive a handover request, which indicates that theterminal device performs a handover from the original base station tothe base station, from an original base station, obtain the first targetuplink carrier, configured for the terminal device to transmit therandom access preamble, among the plurality of uplink carriers accordingto the handover request and transmit handover response information tothe original base station, the handover response information includingthe carrier identifier of the first target uplink carrier to enable theoriginal base station to transmit handover command information includingthe carrier identifier of the first target uplink carrier to theterminal device.

In an embodiment of the disclosure, the above second processor is alsoconfigured to transmit reconfiguration information to the terminaldevice after the base station re-establishes an SCG or modifies the SCGand the reconfiguration information including the carrier identifier ofthe first target uplink carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to transmit a power threshold to the terminal device toenable the terminal device to determine the first target uplink carrierfor transmitting the random access preamble, among the plurality ofuplink carriers corresponding to the base station, according to thepower threshold and an RSRP of a current downlink carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to transmit a quality threshold to the terminal device toenable the terminal device to determine the first target uplink carrierfor transmitting the random access preamble, among the plurality ofuplink carriers corresponding to the base station, according to thequality threshold and an RSRQ of a current downlink carrier.

In an embodiment of the disclosure, the above second processor is alsoconfigured to obtain the second target uplink carrier, configured forthe terminal device to transmit scheduled transmission information,among the plurality of uplink carriers according to the random accesspreamble transmitted by the terminal device.

A random access device is provided in the embodiments of the disclosureand the device can determine, among the plurality of uplink carriers,the first target uplink carrier for transmitting the random accesspreamble and transmit the random access preamble to the target basestation using the first target uplink carrier, so that the random accessis implemented in cells configured with the SUL carrier, thus thesuccess rate of the random access is increased.

As to the device according to the above embodiments, detailed operationsperformed by respective modules in the device are already described indetailed in the embodiments related to the method, and will not beelaborated herein.

FIG. 8 is a structural block diagram illustrating a random access device80 according to an exemplary embodiment. For example, the device 80 maybe a mobile phone, a computer, a digital broadcast terminal, a messagingdevice, a gaming console, a tablet, a medical device, exercise equipmentand a personal digital assistant and so on.

The device 80 may include one or more of the following components: aprocessing component 802, a memory 804, a power component 806, amultimedia component 808, an audio component 810, an Input/Output (I/O)interface 812, a sensor component 814, and a communication component816.

The processing component 802 typically controls overall operations ofthe device 80, such as the operations associated with display, telephonecalls, data communications, camera operations, and recording operations.The processing component 802 may include one or more processors 820 toexecute instructions to perform all or part of the operations in theabove-mentioned method. Moreover, the processing component 802 mayinclude one or more modules which facilitate interaction between theprocessing component 802 and the other components. For instance, theprocessing component 802 may include a multimedia module to facilitateinteraction between the multimedia component 808 and the processingcomponent 802.

The memory 804 is configured to store various types of data to supportthe operation of the device 80. Examples of such data includeinstructions for any application programs or methods operated on thedevice 80, contact data, phonebook data, messages, pictures, video, etc.The memory 804 may be implemented by any type of volatile ornon-volatile memory devices, or a combination thereof, such as a StaticRandom Access Memory (SRAM), an Electrically Erasable ProgrammableRead-Only Memory (EEPROM), an Erasable Programmable Read-Only Memory(EPROM), a Programmable Read-Only Memory (PROM), a Read-Only Memory(ROM), a magnetic memory, a flash memory, and a magnetic or opticaldisk.

The power component 806 provides power for various components of thedevice 80. The power component 806 may include a power managementsystem, one or more power supplies, and other components associated withgeneration, management and distribution of power for the device 80.

The multimedia component 808 includes a screen providing an outputinterface between the device 1100 and a user. In some embodiments, thescreen may include a Liquid Crystal Display (LCD) and a Touch Panel(TP). If the screen includes the TP, the screen may be implemented as atouch screen to receive an input signal from the user. The TP includesone or more touch sensors to sense touches, swipes and gestures on theTP. The touch sensors may not only sense a boundary of a touch or swipeaction but also detect a duration and pressure associated with the touchor swipe action. In some embodiments, the multimedia component 808includes a front camera and/or a rear camera. The front camera and/orthe rear camera may receive external multimedia data when the device 80is in an operation mode, such as a photographing mode or a video mode.The front camera and/or the rear camera may receive external multimediadata when the device 80 is in an operation mode, such as a photographingmode or a video mode.

The audio component 810 is configured to output and/or input an audiosignal. For example, the audio component 810 includes a Microphone(MIC), and the MIC is configured to receive an external audio signalwhen the device 80 is in an operation mode, such as a call mode, arecording mode and a voice recognition mode. The received audio signalmay further be stored in the memory 804 or sent through thecommunication component 816. In some embodiments, the audio component810 further includes a speaker configured to output the audio signal.

The I/O interface 812 provides an interface between the processingcomponent 802 and a peripheral interface module, and the peripheralinterface module may be a keyboard, a click wheel, a button and thelike. The button may include, but not limited to: a home button, avolume button, a starting button and a locking button.

The sensor component 814 includes one or more sensors configured toprovide status assessment in various aspects for the device 80. Forinstance, the sensor component 814 may detect an on/off status of thedevice 80 and relative positioning of components, such as a display andsmall keyboard of the device 80, and the sensor component 814 mayfurther detect a change in a position of the device 80 or a component ofthe device 80, presence or absence of contact between the user and thedevice 80, orientation or acceleration/deceleration of the device 1100and a change in temperature of the device 80. The sensor component 814may include a proximity sensor configured to detect presence of anobject nearby without any physical contact. The sensor component 814 mayalso include a light sensor, such as a Complementary Metal OxideSemiconductor (CMOS) or Charge Coupled Device (CCD) image sensor,configured for use in an imaging application. In some embodiments, thesensor component 814 may also include an acceleration sensor, agyroscope sensor, a magnetic sensor, a pressure sensor or a temperaturesensor.

The communication component 816 is configured to facilitate wired orwireless communication between the device 80 and another device. Thedevice 80 may access a communication-standard-based wireless network,such as a Wireless Fidelity (WiFi) network, a 2nd-Generation (2G) or3rd-Generation (3G) network or a combination thereof. In an exemplaryembodiment, the communication component 816 receives a broadcast signalor broadcast associated information from an external broadcastmanagement system through a broadcast channel. In an exemplaryembodiment, the communication component 816 further includes a NearField Communication (NFC) module to facilitate short-rangecommunication. For example, the NFC module may be implemented based on aRadio Frequency Identification (RFID) technology, an Infrared DataAssociation (IrDA) technology, an Ultra-WideBand (UWB) technology, aBluetooth (BT) technology and another technology.

In an exemplary embodiment, the device 1100 may be implemented by one ormore Application Specific Integrated Circuits (ASICs), Digital SignalProcessors (DSPs), Digital Signal Processing Devices (DSPDs),Programmable Logic Devices (PLDs), Field Programmable Gate Arrays(FPGAs), controllers, micro-controllers, microprocessors or otherelectronic components, and is configured to execute the abovementionedmethod.

In an exemplary embodiment, there is also provided a non-transitorycomputer-readable storage medium including an instruction, such as thememory 804 including an instruction, and the instruction may be executedby the processor 820 of the device 80 to implement the abovementionedmethod. For example, the non-transitory computer-readable storage mediummay be a Read-Only Memory (ROM), a Random Access Memory (RAM), a CompactDisc Read-Only Memory (CD-ROM), a magnetic tape, a floppy disc, anoptical data storage device and the like.

FIG. 9 is a structural block diagram illustrating a random access device90 according to an exemplary embodiment. For example, the device 90 maybe provided as a server that is applied to a base station. The device 90includes a processing component 902 and further includes one or moreprocessors and a memory resource represented by a memory 902, whichstores instructions (such as an application) executable by theprocessing component 902. The applications stored in the memory 903 mayinclude one or more modules, each of which corresponds to a group ofinstructions. Moreover, the processing component 902 is configured toexecute the instructions to perform the above methods.

The device 90 may further include a power component 906, which isconfigured to conduct power management of the device 90, one wired orwireless network interface 905, which is configured to connect thedevice 90 to a network and one I/O interface 908. The device 90 canoperate an operation system stored in the memory 903, such as WindowsServer™, Mac OS X™, Unix™, Linux™, FreeBSD™ and the like.

A non-transitory computer readable storage medium is provided in theembodiments of the disclosure. When instructions in the storage mediumis executed by the processor of the device 80, the device 80 can executethe above random access method at the terminal device side. The methodincludes the following operations.

A first target uplink carrier is determined among a plurality of uplinkcarriers corresponding to a target base station, the plurality of uplinkcarriers including at least one SUL carrier.

A random access preamble is transmitted to the target base station usingthe first target uplink carrier.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operations: a carrieridentifier of the first target uplink carrier is received from thetarget base station; and the first target uplink carrier is determinedamong the plurality of uplink carriers corresponding to the target basestation according to the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, receiving the carrier identifier ofthe first target uplink carrier from the base station includes thefollowing operation: an RRC message, which is the carrier identifier ofthe first target uplink carrier, is received from the target basestation.

In an embodiment of the disclosure, receiving the carrier identifier ofthe first target uplink carrier from the base station includes thefollowing operation: allocation information of the random accesspreamble is received from the target base station, the allocationinformation of the random access preamble including the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, receiving the carrier identifier ofthe first target uplink carrier from the base station includes thefollowing operation: handover command information from an original basestation is received when the terminal device performs handover betweenthe original base station and the target base station, the handovercommand information including the carrier identifier of the first targetuplink carrier.

In an embodiment of the disclosure, receiving the carrier identifier ofthe first target uplink carrier from the base station includes thefollowing operation: reconfiguration information is received from thetarget base station after the target base station re-establishes an SCGor modifies the SCG, the reconfiguration information including thecarrier identifier of the first target uplink carrier.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operations: an RRC messageincluding a power threshold is received from the target base station; anRSRP of a current downlink carrier is detected; and the first targetuplink carrier is determined among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold.

In an embodiment of the disclosure, the plurality of uplink carriersincludes one SUL carrier and one non-SUL carrier; determining the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold includes the following operations: the non-SUL carrieris determined as the first target uplink carrier in response to the RSRPbeing greater than or equal to the power threshold; and the SUL carrieris determined as the first target uplink carrier in response to the RSRPbeing less than the power threshold.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operations: an RRC messageincluding a quality threshold is received from the target base station;an RSRQ of the current downlink carrier is detected; and the firsttarget uplink carrier is determined among the plurality of uplinkcarriers corresponding to the target base station according to the RSRQand the quality threshold.

In an embodiment of the disclosure, the plurality of uplink carriersincludes one SUL carrier and one non-SUL carrier; determining the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRQ and thequality threshold includes the following operations: the non-SUL carrieris determined as the first target uplink carrier in response to the RSRQbeing greater than or equal to the quality threshold; and the SULcarrier is determined as the first target uplink carrier in response tothe RSRQ being less than the quality threshold.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operations: an RRC messageincluding the power threshold and the quality threshold is received fromthe target base station; the RSRP and the RSRQ of the current downlinkcarrier is detected; and the first target uplink carrier is determinedamong the plurality of uplink carriers corresponding to the target basestation according to the RSRP and the power threshold as well as theRSRQ and the quality threshold.

In an embodiment of the disclosure, the plurality of uplink carriersincludes one SUL carrier and one non-SUL carrier; determining the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold includesthe following operations: the non-SUL carrier is determined as the firsttarget uplink carrier in response to the RSRP being greater than orequal to the power threshold, or in response to the RSRQ being greaterthan or equal to the quality threshold; and the SUL carrier isdetermined as first target uplink carrier in response to the RSRP beingless than the power threshold and the RSRQ being less than the qualitythreshold.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operation: a carrierconfigured with a PUCCH among the plurality of uplink carriers isdetermined as the first target uplink carrier.

In an embodiment of the disclosure, determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station includes the following operation: the first targetuplink carrier is determined according to a random access resourceincluded in each of the plurality of uplink carriers.

In an embodiment of the disclosure, the method further includes thefollowing operations: random access response information is receivedfrom the target base station, the random access response informationincluding the carrier identifier of a second target uplink carrier; thesecond target uplink carrier is determined among the plurality of uplinkcarriers corresponding to the target base station according to thecarrier identifier of the second target uplink carrier; and scheduledtransmission information is transmitted to the target base station usingthe second target uplink carrier.

In an embodiment of the disclosure, the method further includes thefollowing operations: a third target uplink carrier is determined amongthe plurality of uplink carriers corresponding to the target basestation if random access response information is not received from thetarget base station in a second preset period; and the random accesspreamble is transmitted to the target base station using the thirdtarget uplink carrier.

In an embodiment of the disclosure, transmitting the random accesspreamble to the target base station using the third target uplinkcarrier includes the following operations: a transmitting power, withwhich the random access preamble is transmitted to the target basestation, is obtained using the first target uplink carrier; and therandom access preamble is transmitted to the target base station on thethird target uplink carrier with the transmitting power.

A non-transitory computer readable storage medium is provided in theembodiments of the disclosure. When instructions in the storage mediumis executed by the processor of the device 90, the device 90 can executethe above random access method at the base station side. The methodincludes the following operation.

Indication information is transmitted to a terminal device, theindication information being configured to indicate a first targetuplink carrier to be determined, by the terminal device for transmittinga random access preamble, among a plurality of uplink carrierscorresponding to the base station, and the plurality of uplink carriersincluding at least one SUL carrier.

In an embodiment of the disclosure, the method further includes thefollowing operation: the first target uplink carrier configured for theterminal device to transmit the random access preamble is obtained amongthe plurality of uplink carriers; transmitting the indicationinformation to the terminal device includes the following operation: acarrier identifier of the first target uplink carrier is transmitted tothe terminal device to enable the terminal device to determine,according to the carrier identifier of the first target uplink carrier,the first target uplink carrier among the plurality of uplink carrierscorresponding to the base station.

In an embodiment of the disclosure, obtaining, among the plurality ofuplink carriers, the first target uplink carrier configured for theterminal device to transmit the random access preamble includes thefollowing operation: the first target uplink carrier configured for theterminal device to transmit the random access preamble is obtainedaccording to a random access resource included in each of the pluralityof uplink carriers.

In an embodiment of the disclosure, transmitting the carrier identifierof the first target uplink carrier to the terminal device includes: anRRC message including the carrier identifier of the first target uplinkcarrier is transmitted to the terminal device.

In an embodiment of the disclosure, transmitting the carrier identifierof the first target uplink carrier to the terminal device includes:allocation information of the random access preamble is transmitted tothe terminal device, the allocation information of the random accesspreamble including the carrier identifier of the first target uplinkcarrier.

In an embodiment of the disclosure, obtaining, among the plurality ofuplink carriers, the first target uplink carrier configured for theterminal device to transmit the random access preamble includes thefollowing operations: a handover request, which indicates that theterminal device performs handover from the original base station to thebase station, is received from an original base station; the firsttarget uplink carrier configured for the terminal device to transmit therandom access preamble is obtained among the plurality of uplinkcarriers according to the handover request; transmitting the carrieridentifier of the first target uplink carrier to the terminal deviceincludes the following operation: handover response information istransmitted to the original base station, the handover responseinformation including the carrier identifier of the first target uplinkcarrier to enable the original base station to transmit, to the terminaldevice, handover command information including the carrier identifier ofthe first target uplink carrier.

In an embodiment of the disclosure, transmitting the carrier identifierof the first target uplink carrier to the terminal device includes thefollowing operation: reconfiguration information is transmitted to theterminal device after the base station re-establishes an SCG or modifiesthe SCG, the reconfiguration information including the carrieridentifier of the first target uplink carrier.

In an embodiment of the disclosure, transmitting the indicationinformation to the terminal device includes the following operation: apower threshold is transmitted to the terminal device to enable theterminal device to determine, according to the power threshold and anRSRP of a current downlink carrier, the first target uplink carrier fortransmitting the random access preamble among the plurality of uplinkcarriers corresponding to the base station.

In an embodiment of the disclosure, transmitting the indicationinformation to the terminal device includes the following operation: aquality threshold is transmitted to the terminal device to enable theterminal device to determine, according to the quality threshold and anRSRQ of the current downlink carrier, the first target uplink carrierfor transmitting the random access preamble among the plurality ofuplink carriers corresponding to the base station.

In an embodiment of the disclosure, the method further includes: asecond target uplink carrier configured for the terminal device totransmit scheduled transmission information is obtained among theplurality of uplink carriers according to the random access preambletransmitted by the terminal device; random access response informationis transmitted to the terminal device, the random access responseinformation including the carrier identifier of the second target uplinkcarrier.

Other implementation solutions of the present disclosure will beapparent to those skilled in the art from consideration of thespecification and practice of the present disclosure. The presentapplication is intended to cover any variations, uses, or adaptations ofthe present disclosure following the general principles thereof andincluding such departures from the present disclosure as come withinknown or customary practice in the art. It is intended that thespecification and examples be considered as exemplary only, with a truescope and spirit of the present disclosure being indicated by thefollowing claims.

It will be appreciated that the present disclosure is not limited to theexact construction that has been described above and illustrated in theaccompanying drawings, and that various modifications and changes may bemade without departing from the scope thereof. It is intended that thescope of the present disclosure only be limited by the appended claims.

1. A random access method, comprising: determining a first target uplinkcarrier among a plurality of uplink carriers corresponding to a targetbase station, the plurality of uplink carriers comprising at least onesupplementary uplink (SUL) carrier; and transmitting a random accesspreamble to the target base station using the first target uplinkcarrier.
 2. The method according to claim 1, wherein determining thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station comprises: receiving a carrieridentifier of the first target uplink carrier from the target basestation; and determining the first target uplink carrier among theplurality of uplink carriers corresponding to the target base stationaccording to the carrier identifier of the first target uplink carrier.3. The method according to claim 2, wherein receiving the carrieridentifier of the first target uplink carrier from the base stationcomprises: receiving a radio resource control (RRC) message from thetarget base station, the RRC message comprising the carrier identifierof the first target uplink carrier.
 4. The method according to claim 2,wherein receiving the carrier identifier of the first target uplinkcarrier from the base station comprises: receiving allocationinformation of the random access preamble from the target base station,the allocation information of the random access preamble comprising thecarrier identifier of the first target uplink carrier.
 5. The methodaccording to claim 2, wherein receiving the carrier identifier of thefirst target uplink carrier from the base station comprises: receivinghandover command information from an original base station, the handovercommand information comprising the carrier identifier of the firsttarget uplink carrier.
 6. The method according to claim 2, whereinreceiving the carrier identifier of the first target uplink carrier fromthe base station comprises: receiving reconfiguration information fromthe target base station after the target base station re-establishes asecondary cell group (SCG) or modifies the SCG, the reconfigurationinformation comprising the carrier identifier of the first target uplinkcarrier.
 7. The method according to claim 1, wherein determining thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station comprises: receiving an RRCmessage from the target base station, the RRC message comprising a powerthreshold; detecting a reference signal received power (RSRP) of acurrent downlink carrier; and determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station according to the RSRP and the power threshold. 8.The method according to claim 7, wherein the plurality of uplinkcarriers comprise an SUL carrier and a non-SUL carrier, determining thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold comprises: determining the non-SUL carrier as the firsttarget uplink carrier in response to the RSRP being greater than orequal to the power threshold; and determining the SUL carrier as thefirst target uplink carrier in response to the RSRP being less than thepower threshold.
 9. The method according to claim 1, wherein determiningthe first target uplink carrier among the plurality of uplink carrierscorresponding to the target base station comprises: receiving an RRCmessage from the target base station, the RRC message comprising aquality threshold; detecting a reference signal received quality (RSRQ)of a current downlink carrier; and determining the first target uplinkcarrier among the plurality of uplink carriers corresponding to thetarget base station according to the RSRQ and the quality threshold. 10.The method according to claim 9, wherein the plurality of uplinkcarriers comprise an SUL carrier and a non-SUL carrier, determining thefirst target uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRQ and thequality threshold comprises: determining the non-SUL carrier as thefirst target uplink carrier in response to the RSRQ being greater thanor equal to the quality threshold; and determining the SUL carrier asthe first target uplink carrier in response to the RSRQ being less thanthe quality threshold.
 11. The method according to claim 1, whereindetermining the first target uplink carrier among the plurality ofuplink carriers corresponding to the target base station comprises:receiving an RRC message from the target base station, the RRC messagecomprising a power threshold and a quality threshold; detecting an RSRPand an RSRQ of a current downlink carrier; and determining the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold.
 12. Themethod according to claim 11, wherein the plurality of uplink carrierscomprise an SUL carrier and a non-SUL carrier, determining the firsttarget uplink carrier among the plurality of uplink carrierscorresponding to the target base station according to the RSRP and thepower threshold as well as the RSRQ and the quality threshold comprises:determining the non-SUL carrier as the first target uplink carrier inresponse to the RSRP being greater than or equal to the power threshold,or in response to the RSRQ being greater than or equal to the qualitythreshold; and determining the SUL carrier as first target uplinkcarrier in response to the RSRP being less than the power threshold andthe RSRQ being less than the quality threshold.
 13. The method accordingto claim 1, wherein determining the first target uplink carrier amongthe plurality of uplink carriers corresponding to the target basestation comprises: determining, as the first target uplink carrier, acarrier configured with a physical uplink control channel (PUCCH) amongthe plurality of uplink carriers.
 14. The method according to claim 1,wherein determining the first target uplink carrier among the pluralityof uplink carriers corresponding to the target base station comprises:determining the first target uplink carrier according to a random accessresource comprised in each of the plurality of uplink carriers.
 15. Themethod according to claim 1, further comprising: receiving random accessresponse information from the target base station, the random accessresponse information comprising a carrier identifier of a second targetuplink carrier; determining the second target uplink carrier among theplurality of uplink carriers corresponding to the target base stationaccording to the carrier identifier of the second target uplink carrier;and transmitting scheduled transmission information to the target basestation using the second target uplink carrier.
 16. (canceled) 17.(canceled)
 18. A random access method, comprising: transmittingindication information to a terminal device, wherein the indicationinformation is configured to indicate a first target uplink carrier tobe determined, by the terminal device for transmitting a random accesspreamble, among a plurality of uplink carriers corresponding to a basestation, the plurality of uplink carriers comprising at least onesupplementary uplink (SUL) carrier.
 19. The method according to claim18, further comprising: obtaining, among the plurality of uplinkcarriers, the first target uplink carrier configured for the terminaldevice to transmit the random access preamble, wherein transmitting theindication information to the terminal device comprises: transmitting acarrier identifier of the first target uplink carrier to the terminaldevice to enable the terminal device to determine the first targetuplink carrier among the plurality of uplink carriers corresponding tothe base station according to the carrier identifier of the first targetuplink carrier. 20.-54. (canceled)
 55. A random access device,comprising: a processor; and a memory configured to store instructionsexecutable by the first processor, wherein the processor is configuredto determine a first target uplink carrier among a plurality of uplinkcarriers corresponding to a target base station, the plurality of uplinkcarriers comprising at least one supplementary uplink (SUL) carrier; andtransmit a random access preamble to the target base station using thefirst target uplink carrier.
 56. A random access device, comprising: aprocessor; and a memory configured to store instructions executable bythe processor; wherein the processor is configured to transmitindication information to a terminal device, wherein the indicationinformation is configured to indicate a first target uplink carrier tobe determined, by the terminal device for transmitting a random accesspreamble, among a plurality of uplink carriers corresponding to the basestation, and the plurality of uplink carriers comprises at least onesupplementary uplink (SUL) carrier.
 57. (canceled)
 58. (canceled)